General
This is a guide to the setup that I use to complete maps on legend difficulty playing solo with bots. This by no means it the best way to set up your bots but I have a very high success rate when playing at legend difficulty using this setup. This setup is in no way min-maxed and is a fairly general setup that doesn't specialise into any particular niche and all weapons and accessories are the same ones that I use when playing.

About myself
At the time of writing this guide I have 2k+ hours of playing Vermintide 2, most of those hours being played solo with bots. I play mostly on legend difficulty, I only play cata to complete each map once for the cata borders on the map screens. I have no interest in modded difficulties as the challenge that legend provides is perfect for me.

Cata and modded difficulties
Whilst I do use this same setup for playing on the cata difficulty it is much less reliable and is inconsistent and for anyone wanting to play at cata difficulty I would recommend perhaps finding other guides that cater specifically to cata. As far as modded difficulties go I've never tested them as I'm personally not that interested in those difficulties and there are definitely better guides that are catered to these difficulties.

Differences to other guides
There are also some choices in this guide that don't align with other more popular guides or with "meta" picks but this setup works for me and there is nothing stopping you from using this guide alongside others to perfect a setup that works for you. If I know of any of these I will point these out as alternatives.

Mods
I do use the "Bot Improvements - Combat" mod by Grimalackt. This mod is currently listed as unsanction when viewed in the mods part of the Vermintide 2 launcher however I do believe it still works. If the game is launched with the mod enabled bots tend to ping elite enemies they are fighting but when disabled they don't, or at the very least don't do it nearly as frequently. I may be incorrect in thinking this but from what I've seen and tested this mod does make a difference even if listed as unsanctioned.

Here I will layout what classes, weapons and talents I select for my bots and give a quick rundown as to why I choose these specifically.

It should be noted that all of the weapons and accessories I use have 300 power and max percentage properties.

Classes, Talents and Weapons
These are the classes, weapons and talents I use for my bots:

Kruber - Mercenary
Talents: 1-1-2-3-2-3
Melee: Spear and Shield with Attack Speed, Block Cost Reduction and Opportunist.
Ranged: Handgun with Power vs Armoured, Power vs Infantry and Hunter

Mercenary Kruber is a reliable class that is great for supporting you and the other bots. His career skill can keep you and your bots topped up with temp HP as well as knocking specials off other teammates or just creating space within a dense horde.

Bardin - Ironbreaker
Talents: 1-2-3-2-2-1
Melee: Dual Hammers with Attack Speed, Crit Chance and Swift Slaying.
Ranged: Handgun with Power vs Armoured, Power vs Infantry and Hunter

Ironbreaker Bardin is unkillable, for the most part. That's the biggest reason to keep him on the team and probably the bot choice I would recommend the most. So many times he has come in clutch to save the other bots, or me on occasion. An immediate pick for holding onto a Grimoire as if he just never dies. His career skill, though not as noticeable, is very valuable in taking aggro away from you and the other bots and with my talent choice also boosts the power of the team for a short duration.

Kerillian - Sister of the Thorn
Talents: 2-2-3-1-1-3
Melee: Sword and Dagger with Attack Speed, Crit Chance and Swift Slaying.
Ranged: Moonfire Bow with Power vs Armoured, Power vs Infantry and Hunter

Sister of the Thorn really comes down to having great passives and a sometimes helpful career skill. She gives the team boosted healing, heals herself with any excess temp health gained by any teammate when at full health and her blackvenom DOT increases damage dealt to enemies inflicted with it. Whilst she can be annoying sometimes with her career skill bouncing enemies around there have been countless times she's saved bots and myself from specials.

Saltzpyre - Witch Hunter Captain
Talents: 2-3-2-3-2-3
Melee: Axe and Falchion with Attack Speed, Crit Chance and Swift Slaying.
Ranged: Brace of Pistols with Power vs Armoured, Power vs Infantry and Hunter

Witch Hunter Captain has great team utility and is a generally strong class. Increased damage to pinged targets on top of other buffs he can give via his talents. His career skill, like Kruber's, can knock off specials or create space within a dense horde on top of granting 25% crit chance to the team.

Honorable Mentions
I will also mention Grail Knight Kruber and Warrior Priest Saltzpyre which are both really strong classes with some great utility however I choose not to use these classes as they have no ranged capabilities. I know that the bots don't use their ranged nearly as much as they should but having 3 bots that have ranged weapons make it much more likely they will use them to deal with specials that have pinned down teammates.

Melee Weapons
Most of the melee weapons, aside from Kruber's Spear and Shield, all have Attack Speed, Crit Chance and Swift Slaying. This is basically to increase the rate in which attacks can be dealt and the Crit Chance not only improves damage output but also the up-time for Swift Slaying. Now many people would run Block Cost Reduction on all melee weapons, and that is definitely a good choice, however for me the 30% I get from the Necklace is usually enough and I think I personally prefer the extra offensive stats. Kruber's Spear and Shield only has a different property and trait due to it being a shield weapon and, in my opinion, befitting from these alternative property and trait more so.

Ranged Weapons
All of the ranged weapons have Power vs Armoured, Power vs Infantry and Hunter. The properties are their to help deal extra damage to special enemies and armoured enemies, who fall under either or enemy category. The Hunter trait could be swapped out for another trait however since I use the same weapons as my bots I find hunter is just my preferred trait, allowing you to deal with multiple enemies of the same amour class much easier.

I might run through talent choices at a later date but I primarily focus on talents that either buff the team members or increase the bots ability to survive.

Accessories
I use the same accessories across all of my bots:
It should also be noted that I too use these accessories on my character as well

Necklace - Health, Block Cost Reduction, Barkskin

Running Health is fairly obvious as the more health the bots have the more damage they are able to take. Block Cost Reduction allows the bots to be able to block more damage thus allowing them to survive longer. I used to run Boon of Shallya for the increased healing however I now use Barkskin as it helps bots take less damage from gas, gutter runners and other sources of continuous damage. Barkskin also continues to apply if the bot is downed whereas Boon only really helps them when they are on their feet. Either one is probably good enough but I feel Barkskin overall is the better choice.

Charm
Power vs Chaos, Power vs Skaven, Concoction

Power vs Chaos and Skaven just gives a flat percentage damage increase across all enemies in the game. This is where people who min-max these properties will disagree with this choice however as a fairly casual player this flat percentage damage is enough and will in most circumstances always be useful. The trait doesn't matter as bots are unable to use potions.

Trinket
Stamina Recovery, Cooldown Reduction/Curse Resistance, Shrapnel

Stamina Recovery again just like Block Cost Reduction will allow bots to survive longer ensuring that their stamina is recovered quicker and are available to block effectively more often. Cooldown Reduction allows the bots to use their career skills more often and this can potentially save you from a sticky situation. However this can be swapped out for Curse Resistance if you are planning on collecting Grimoires to allow your bots to have more health, I find if the bots do not have Curse Resistance the health penalty when holding two Grimoires is too much for them to handle. The trait doesn't matter as bots are unable to use bombs.

General

When playing with bots at the legend difficulty it is important to stick with your bots and ensure that they don't get too spread out. Losing one bot can be bad, losing more can be a disaster. If you keep your bots alive and healthy they'll be able to support you through the map. Sometimes I will forgo healing supplies to keep bots from dying although I'll generally save it for when they are wounded.

Tomes and Grimoires

Tomes
When it comes to Tomes I will always hold a tome and give the other two tomes to Bardin and Kruber. If I am playing either Bardin or Kruber either Saltzpyre or Kerillian can hold a tome, I would usually give it to Kerillian as Sister of the Thorn can steal extra temp HP with her passive "A Sustenance of Leechlings" perk, thus needing less healing generally.

Grimoires
Grimoires I will always give to either Bardin or Kruber. I usually hold a Grimoire but whether you hold one yourself is up to you. You must consider how badly you want to be victorious regardless of Grimoires or want to try to finish with a Grimoire. If a bot dies with a Grimoire you can still finish the level and you'll have gained back that cursed health after the Grimoire is lost making completing the rest of the level easier. You must also consider how much you use potions, I will usually give the first Grimoire to Bardin/Kruber so I can still use potions until I get to the second Grimoire.

In conclusion, I have used this setup of bots for several months and have found this to be a reliable setup. Though it might not be perfect, min-maxed or suitable to all raki-slayers play styles it has shown me a consistent high success rate.

Whilst I have gone over most of what I wanted to go over I will further update this guide if things change or if I get certain requests to go over things or add things in the future.

Hope this guide helps, thank you for giving it a read.
- JB :)