[read my previous comment first] ...
-also, as Lüng pointed out, cavalry units would be cool, for example (fitting WW1 theme) cavalry with sabres

Also, I agree that planes would be OP, but a small hot air ballon/zeppelin thing dropping bombs would be cool (possibly with a finite amount of bombs so its not totally OP agains mele only armies). That would also give the opportunity of ati aircraft aircraft, attacking only other flying units. I'm talking about ballons the size of a ballista or smaller, flying slowly at the height of no more than 1.5 chicken man man

First, some stuff I think would improve your ideas:
-none of the units should be completely resistant to others (that would be no fun, not being able to destroy a tank with peasants. And also, it would be realistic. Noone likes "realistic" :P)
-artillery should have a blind spot, much bigger than those of ballistas (ballistae?) and catapults, close to it, and be able to fire at enemies at the far end of the map)
-the flame trooper should have a chance (of at most 75%) of exploding on death, creating an area similar to that caused by the barrel roller's explosion

Other than that, I would add these units:

-rifleman - basically musketman with bayonets and slightly better stats

-landmine - stationary barrel roller invisible to the enemy (noone attacks them), possibly a little weaker than barrel roller

-granade thrower, throwing not very powerful granades exploding on contact with something.

continuation in the next comment, steam doesn't accept more than 1000 characters

this could be solved with a workshop

Most of these units are anti-infantary...

That's a good guide you have there.

That is true, but you also have to remember the fact of the games more of a medievial game. Thats why they have ballistas, hwachas. I can understand some of your weapons and troops like flamethrower. I think the artillery crew is basically the ballista.

I do understand that but it's just for a little fun. well you never know something on this list could be added like the maxim gun crew because that could fit with the muskets.

Hey, i'm the guy that made the full Description of each unit guide, and some ideas here are cool, but some may not fit. Just saying.

Planes would be ridiculous as the point of the game is to have the units be stupid. this is an RTS with the user having NO control but where the stuff is placed. with this said, if you placed a plane in this game it'd most likely go out like a Japaneese kamakazi, In the ground exploading.

It wouldnt serve much of a purpose and personally I think this game would be nice with something like Calvery, Horse Musket men with bayonets. However they would use the muskets instead of the bayonets, but if something were to touch the bayonet, it would be insta kill.

Which for this ridiculous game where stuff falls down and can still do damage, I feel that'd make sense. a Landship though. Sounds a bit extreme. Then again this is Pre-alpha. who knows maybe we'll advance eras and see stuff like this?

I think riflemen from diffrent eras would be intresting, like cowboy rifle men who run around using lever action, or WWI riflemen who lie down or take cover behind rocks. And the smg troopers would be mobile machine guns who dont shoot as fast or powerfull