I kinda wanna see a MG team, low HP, low numbers, but huge ammo capacity and fire rate and great range...one of these with unobstructed view can melt five elite units and have ammo left over if managed properly...but again, you need to manage it, cause it is easy to kill with cav or arrows...

I suppose the closest we get to that is the Helblaster Volley Gun. I'd like to see other models of handguns, too, though. I typically model at least the reload time off historical examples, like the fastest I've ever seen anyone reload a muzzle-loader is in 15 seconds the and fastest I've ever seen someone reload a breech-style Ferguson rifle is around 10. If you max rank the Musketeers and Riflemen or Guards, you'll see the reload time comes close to around that mark for each.

I tend to keep to some historical accounts of guns and their range, and then model damage or other unit strengths around that. Range tends to be picked up from other Total War titles, and based on some historical accounts to an extent. I'd reduce Musket range to 80 meters or so, but being so close to the range of pistols seemed unfitting. As it is in vanilla, 100 range only skirts above the 90 range of Free Company pistols. Stills, the lack of accuracy more or less handles that. Riflemen and Guards follow the precedent of Ferguson Riflemen in Empire: Total War, although the actual weapon has a range of about 200 meters. Repeater Riflemen range is loosely based on the effective range of the Spencer 1870 repeater, albeit short about 90 meters (it's getting increased to 360 from 250 soon, snipers ahoy.)

I got kinda sidetracked. Muzzle-loading smoothbore and breech-loading rifled firearms existed and can feasibly be imagined with the handgun models, but I'd like to see guns with percussion cap mechanisms (plausibly faster breech-loading times) and bayonets, for anti-large melee Line Infantry like High Elves already have with their fancy militia. Reloading animations for firearms would be nice as well.

That's probably not gonna happen...but you could have later periods of units...up to you of course...

Repeater rifles seems as advanced as it gets for handheld firearms.

While the model wouldn't convey it, lever action repeaters could be doable...or breach loaders...*Men of Harlech starts playing*