Okey, I agree. But what would you suggest they do it fix this?
Manpower
A rework on how manpower works. First of all, greatly reducing its size. No more goddamning 1'000'000 dudes awaiting the call. Second, tieing it to seasons. Example: during Some months it should drop to almost 0 since most soldiers return to their fields. Professional troops could have a separate manpower pool or something like that, but only big or advanced countries (late game technologies) should afford a big number of them.
Recap: dividing units in national conscripts, auxilia and professionals. Each type with his own manpower pool.
Unit cap and type
Unit available to hire should be based on your pops types. Example: 10 Freemen pops-->1 archer/light infantry/light cavalry unit (these are random numbers). 10 Citizens-->1 Heavy cavalry/Heavy infantry. Another Example: 10 Nobles-->
2 heavy cavalry/heavy infantry. Cultures can change things, example: Rome, 10 roman/italic freemen-->1 Heavy infantry even if they arent nobles.
This leads to...
Costly and fewer Battles, at least in early to mid game. Battles should be bloodier, with more casualties.
Most casualties should be prisoners-->slaves. Make
another (yeah, i know, im sorry) special pools for prisoners caught in battle, because back then they were a precious resource, used for ransom or made into slaves. Maybe you can even have different captured enemies types, dunno. Options on how to use them during the peace treaty, spend them for war score/opinion points, ransom them, make them into slaves, sodomize them for troops morale boost (yep that happened, but im joking) or whatever you feel is fitting.
BATTLE
Rework teh TAhctics. Yep, they are a pain in the butt. Maybe a HOI4 approach would fit pretty good. Your generals should have a chance to roll the best tactic to counter his adversary, based on his ability. New Tacticts unlockable though techs, national ideas, culture, blah blah...
Jesus, add Battle types, please. Ambush/Open fields/Hill fighting etc. The type should be rolled before a battle commence, based on your army composition, your generals' skills, the province terrain. Special battle types available for some cultures: Notable Example: ze germans can execute a powerful ambush in dense forest, using their light infantry and cavalry based armies.
OK, I think adding the caravan troop type was a step in the right direction. BUT please add tactics available to high skilled generals which could allow to attack the caravan troops type, it was a valid but risky tactic back then. If they are destroyed, a hit to the army's morale (and of course to the resources to keep going on).
I already said battles should be costly for the losing side. After the especially bloody battle of Cannae Rome had to wait years for the new generations to grow up. Cannae is an outlier, Battles shouldnt be THAT bloody, at least most of the time.
Mercenaries
Thats a tough one, because mercenaries were widely used by almost everyone back then. So you cant just drastically reduce their numbers...WAIT, you actually can, since the manpower and number of available troops has been nerfed to the ground in the manpower paragraph. Cool, now make the mercenary bands smaller, cheaper and more widespread. Once you are in a war you can call them, if you have the coins. But you can hire only those bands who have a clear path to your nation, meaning you cant hire a mercenary band that has to waltz its way through enemy territory. Last thing, you should not be able to hire bands too far from you.
No replenishment for mercenary bands during wars.
I hope I wrote all of this in an understandable english. As you see, there are many options to make the game more historical and spice things up a bit. But Imperator rome as of now is a lazy product, it lacks soul, it's the equivalent of an EU4
clone. perhaps it is even doomed, and thats a shame.