One thing that's absolutely needed is a mechanic to increase army costs with civilization level. It was one thing for Rome to expand throughout Italy with an army made up of peasant smallholders, who were needed back on the farm by harvest time. It was another to maintain ~700,000 men in the field, permanently; equip them, provision them, pay them and, ultimately, provide for their pensions. That expense gutted Rome (in conjunction with some other things) and it should be reflected on the game's balance sheet. In one of these streams, I'm seeing the Romans field ~350,000 men on campaign in Gaul around 70BC, like it's nothing, while building a massive surplus (5,000+ gold in the bank). They controlled modern day Algeria, half of Gaul and the Italian boot, at the time (in the game). No fucking chance, mate.
As in, it's not the army numbers themselves that bother me (yes, the army was hundreds of thousands strong by early AD), but what those numbers entail, financially.
I'd introduce the following to make the game a bit more realistic:
1) Theatre level supply limits - the Romans could not maintain ~60 legions in one campaign theatre at any point during their history. Not even with all of the Med supplying them. I shouldn't be watching a battle between 200,000 Romans and 300,000 Pritanians in a single province, unless mass starvation and rampant disease followed. These numbers were not achievable on any single battlefield until, essentially, the early industrial period. Even when history records such numbers (for example, the Persian armies arrayed against the Greeks/Alexander), anything over 100,000 men can basically be disregarded as propaganda. For example, when the Romans fought the Belgae and recorded 290,000 Belgae in the army brought to bear against Caesar's forces, that number basically included ALL Belgae persons (women, children, elderly, infirm) and there were unlikely more than ~60,000 fighting men the Romans had to deal with.
2) Supply distance costs - The further an army has to fight from its supply depots, the more it should cost. Provisioning men in the field is no simple thing. Armies should cost more to maintain as larger numbers of wagons/horses/carts are required to keep them fed. Some of this should be offset by foraging, but this offset should be limited by regional fertility AND local unrest/economic devastation.
2b) Time-based attrition - The longer an army is out on campaign, the more attrition needs to play a role. Armies on campaign for YEARS need to be periodically hit with disease/desertion based attrition, with the only remedy being a sustained opportunity for rest and recuperation. Unit replenishment outside of home territories should be heavily restricted and extremely costly.
3) Solve the army chase - The good old Clausewitz engine battlefield victory followed by months/years of chasing a constantly replenishing enemy army around before its final destruction could be solved simply. If the army is decisively beaten in the field (say, >40% losses and total morale breakdown), it should have a high chance of losing its baggage train and suffering HUGE attrition within the next few months (before, essentially, melting away, if not in a friendly province for sustained R&R).
5) Army costs increase with civilization level - It should cost a lot more for Romans/Macedonians/Carthaginians to field 30,000 men than for the Nervii to do the same, for the reasons outlined further above. However, without any mitigating factors (terrain/circumstances/luck/leadership), a civilised army should put its less civilised counterparts to the sword fairly routinely. They just had too many institutional advantages (training, discipline, equipment, small unit leadership etc) to allow warrior societies to fight them on an even playing field. This would also create a sense of progression for the tribal cultures, wherein their reform toward civilisation would entail a change in fighting styles (and, consequently, costs).
None of this stuff requires a tactical engine, and all the mechanics could be implemented fairly straightforwardly, though maybe not at the modder level. One can hope.
. I just finished my ROME game in "Imperium Universalis " and it is far superior than this "game",i urge anyone to try it out over this shit.
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