-Levelling the Heroes your bots will be gives them access to your talent trees which is important in allowing your bots to be powerful. They also have the gear your equip to those heroes

-Install the Bot Combat Improvement Mod, it helps
https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1395655171&searchtext=

Your bots have a weakness most players learning the game have, they can't deal with everything going on in the game. Typically they buckle under 3 (or even 2) things from the next list at the same time.

1. Horde
2. Special Wave
3. Boss event
4. Patrol

So its your job to take care of whatever your bots will end up struggling with. If a boss appears you will either have to kill it or control the horde. If you chose melee bots assume you will have to shoot specials, and if a patrol appear you should just throw bombs at it. Whichever hero you pick know you will be carrying the majority of the weight in the party and that's just the way it is. Typically I go a boss killing class or a horde control/clear class if I'm going for grims/tomes, but you can roll anything and get clears with or without grims so just play whatever you like to play.

Notable picks for your own hero
1. Foot Knight Kruber (for the aura, bots stay close generally, you can stun lock boss)
2. Mercenary Kruber (give your team attack speed)
3. Boss killers (if you melt the boss your runs are generally wipe free)

Picks your bots

I'll run through notable picks from each hero that you can bring and list the weapon I make them use. I generally run armor piercing weapons to pop elites.

Footknight Kruber - Executioner Sword - Handgun
Damage reduction, free stamina with aura if you chose that talent, sometimes charges enemy threats. Lol. Don't rely on his special to save you from elites, although with handgun he can reliably shoot them when they are close enough. Make him take grims.

Mercenary Kruber - Executioner Sword - Handgun
Sometimes procs his sweeping strikes, which can be nice. Uses his ult on cooldown, which can be pretty helpful. Sometimes it isnt, but generally more useful than Footknight kruber bot ults. Both are solid picks.

Slayer Bardin - Great Axe
This guy usually dies last, so give him the grim. Sometime stuns Chaos Warriors with his Axe. Watch him during Skaven hordes, sometimes gets overwhelmed. Sometimes he leaps to his death. Watch out for that.

Ranger Bardin - Great Axe? - Handgun
If you are going a pot chugging build or really want bombs bring this guy. He will die much sooner than Slayer Bardin but you get ammo and potions. Sometimes he pops his ult when he is about to die and then you get aggro, and thats fun sometimes.

Waystalker Kerellian - Glaive - Longbow
I have never seen a human being use the WayStalker ult like Kerellian bot, sometimes it destroys 2 specials, 3 elites, or just pulls a patrol. These days she pulls less patrols than in earlier builds. Her and Bardin compete for most bot kills. Don't leave her stranded, she will die. In my opinion, best bot in game.

Handmaiden Kerellian - Glaive - Longbow
If you want that stamina aura, here you go. I dont like this option, but you can hit some crazy breakpoints with a handmaiden bot.

Shade Kerellian - Dual Swords / Glaive - Longbow
Sometimes she ults and bops a special, sometimes she ults during bosses. Might be interesting with potion share. I used this bot a lot when Waystalker Kerellian kept pulling patrols on sight.

Zealot Saltspyre - 2 Handed Sword - Brace of Pistols
The pinnacle of Salts bots. Better than Sienna bots, at least. I haven't unlocked his dlc weapon so I have not tested it on him but I feel he dies less with 2 handed sword and the horde clear generally helps the other bots. His Brace of Pistols allows him to pop specials pretty fast. I tried the crossbow as well and prefer BoP, but use whatever works for you.

With Hunter Captain Saltz
This Saltz usually dies but with the Bot Improvement Mods your bots ping elites attacking them giving you more damage. Also gives you damage on boss for pinging. If you run this and Kruber you get A LOT of AoE shouts ccing horde, its gimmicky but can be effective.

I keep it very simple when it comes to bot properties.

Weapon: Attack Speed, Crit Chance, Swiftslaying
Ranged: Breakpoint related killing specials
Necklace: 2 Stamina, 20% Health, Improved Healing (there is probably a better option, haven't tried much else for necks)
Charm: Attack Speed, Power VS Chaos, Trait doesn't matter for bots
Trinket: Crit Chance, Curse Resistance / Movespeed depending on what you are doing

Not sure if bots benefit much from melee breakpoints, i just pray they crit with their weapon. Movespeed if not picking up grims, I like movespeed. They seem to die less when they can escape more.

The real important part of the guide. I'm going to list various concepts that going forward you need to embrace.

1. Keep your pace up.
If you are going for grim/tomes move quickly for them, your bots follow you so they wont be off somewhere doing something useless most of the time. The faster your do the level the less hordes / special you deal with. On that note...

2. Know your Boss Spawns.
If you hear a horde coming and you know you are about to walk into a place that can trigger a boss, just stop. What usually wipes the human plus 3 bots party is a boss during a horde. Its completely possible to do both at the same time, however. Either control the horde or quick melt the boss. The bots usually focus the boss so I usually focus the horde. Blow through your pots since your bots will hand your theirs.

3. Pray for not Chaos Spawn
Its the worst boss imaginable. The bots cannot dance the grab attack. They can dance bosses pretty well, but not this one. Use bombs or hero abilities to knock bots free. Burn this one down or it will probably kill you. Conversely if you get Storm Fiend while he may burn your party to death he may also kill the entire horde himself.

4. There are some things your bots don't understand, like AoEs
Poison Gas Clouds, Fire Spray from Stormfiend / Flame Rat, sometimes they avoid blightstorm. If another bot goes down in the gas sometimes other bots will follow to try and save them. Its best to clear gas rats as quick as possible or just be far away from clouds.

5. Kill the Horde with your Bots
Standing near your bots and attacking with them makes it easier for everyone to stay alive. Use features that funnel the horde into a choke. Do all the smart things your learned to do to manipulate the horde movement. Your bots stand with you. Whatever your horde clear is, use it. You get all the ammo. And on that note...

6. Use your resources
Your bots carry excess pots and bombs, if it looks like ♥♥♥♥ is hitting the fan I suggest you throw bombs at the situation. 3 bombs kills a chaos patrol. I usually kill patrols if I have the bombs/potions because its fun and because you get huge numbers on the scoreboards, but you can sometimes avoid patrols. Also chug your pots on bosses. Since you get all the ammo make a point of actually using your ammo.

7. Decide if you or the bot will get the Grim first
Sometimes I make Bardin take the first grim because I still want to use pots against the boss (if none have appeared yet). Sometimes Bardin dies with that grim. Make the executive decision. Sometimes I make the bots carry both grims. Protect them.

8. Sometime heal your bots
Sometimes you should heal your bots instead of drinking all the healing, especially in grim runs. If I'm not picking up tomes/grims I usually just chug everything but sometimes its better to have some bots than no bots.

9. You can do Boss Levels with bots.
Although I have yet to try and do it with tomes and grims, all boss levels are entirely possible with bots on Legend. Going a boss killer is preferred but I usually just play Footknight Kruber. The bots do not understand Burblespue Tornado, or much of anything that fight. Watch your back at all times during skittergate bosses, they will focus the boss and not on protecting you. Clear the adds.

Some levels are not created equal, especially for bots. Here is a quick rundown.

Easiest
Screaming Bell, Fort Brach, Convocation of Decay, Righteous Stand, Empire in Flames

Hardest
Athel Yenlui (usually lose a grim here or just die), Against the Grain, Festering Ground (they just walk into the acid, its a pain)

Fort: You can kite endlessly in the first area, there are many place to knock bosses off the edge, you can kite a lot here especially if you went Movement Speed on trinket/talents. The grims are late in the level making this one of the easier levels to 2 grim.

Screaming Bell: One of the Easier ones to 2 grim. Be careful of boss spawn areas, its really easy to go too far and trigger the boss.

Convocation: Never have problems with this level. Burn the boss if it shows up.

Righteous: Since they fixed the grim its become slightly harder. Just make sure when going for either grim there isnt a horde around. Ive whiped a few times praying the bots will handle it only to find out a special wave also spawned and killed everyone along with ambients.

Empire: if you can get a barrel in the market before the event then its smooth sailing. If you get a boss event near the 3rd tome its a free loot die since only trickle horde spawns and no specials appear.

Halescourge: Already mentioned this but the bots do not understand the large center of the room tornado attack he performs. Be warned.

The other boss levels: Be mindful you will probably have to slay the boss. While sometimes they can dance Spinemangler very well sometimes they don't, just make sure to clear the trash mobs during the fights because if too many swarm the bots they are doomed.

Athel: Try to not pull eveything and watch for sneaky ambients. Getting the tomes and grims makes this level significantly longer so try and have a good route planned.

Grain: Something about wide open spaces and forced boss spawns really kills the bots in one way or another. if you are grimming get the second one after the boss.

Festering: You can walk them through the buboes so they take less damage but its a pain. I like doing this level though so I sit through the pain.

DLC levels: I never looked up the tome and grim locations on the dlc levels but in general the pit is pretty short, while the Ubersreik levels can be pretty long, and the pool of acid is not something the bots tend to understand. I will update the DLC levels if I ever do the tome / grim locations, but if you do not do tomes/grims with bots they are generally on par with the other levels in terms of difficulty.

Good luck and have fun. If you find a weapon setup for a bot works better for you, feel free to post here about it. Bot behavior has changed over time, making certain weapons better or worse with them, and it has been many a patch since I have changed my bots weapons. Also if you have Sienna bot tips let me know, I don't use Sienna bot.

3 tomes 1 grim is always soldier's chest, ranalds can make this a general's chest
3 tomes 2 grim and a loot die is always general's chest, ranalds can make it an emperors but its not very frequent