...
- how limiting the number of cav units in your army ? Cav units should represent only a part of the army (up to 40% in Renaissance, up to 20% in Industrial, up to 10% in Modern era - these values are examples) ?
Right now we building the 3.2.1 patch.
Later, we will focus on this point (among others).
I have the feeling that the developers are confusing Civilization with Age of Empires II. In AOE, the Paladin (a kind of heavy cavalry, for those who don't know) is the strongest unit. An encounter of 100 Paladins and and 100 champions (the most powerful swordsman in the game) would result in a win of the paladins. Similarly in Realism Invictus, the Swordsman is awarded a strenght of 6 and the classical-age cavalry with 7. But actually, in normal wars, a company (or group or division whatever) of foot soldiers is larger than a cavalry company. so I think, in Civilization games, a swordsman unit represents -let's say- 1000 men, but a cavalry unit represents -let's say- 500 mounted soldiers. But I think, the designers of Realism Invictus simply assumes, that every unit has the same amount of fighting men in it. That means: one mounted soldier should be stronger than a foot soldier = Classical-age cavalry -> 7 str, Swordsman 6 str. And the AI then produces simply the strongest unit, very similar to the fact that many Age of Empires players would mostly produce Paladins.
The solution might be to simply decrease the strength of cavalry and horse archer, to represent the fact that they are less in numbers. Also strong counter units would discourage the AI from producing many mounted units. I would propose this scheme for the ancient and classical age (which is not too different from the current scheme):
Unit.............Strength...Bonus
Archer................3......+100% vs Light Mounted, +50% vs. Recon; %50 City Defense
Militia.................3......+50% vs Mounted (pretty useless

)
Shortswordsman...4......none
Spearman...........4.......+100% vs Mounted, relative cheap
Huntsman...........4.......+50 Attack vs Melee; good withdrawal chances
Axeman..............5.......none(or something creative like city attack bonus etc.)
Swordsman.........6.......none(or something creative)
Chariot...............4.......%50 Attack vs Melee, Recon; moderate witdrawal chances; collateral damage; appears early; but expensive
Horse Archer.......5.......%50 vs Melee; good withdrawal chances
Cataphract.........6.......moderate withdrawal chances, collateral damage
Of course, all units should have slight bonus/malus according to their civilization for more flavour. Also the mounted units should have city penalty as it is. As you can see, mixture of archer, spearman and swordsman is sufficient and and quite solid, but if you seek some decisive advantage, you should invest in horsemen for their collateral damage. I'd also propose, that the Ranged Aid should provide a very significant bonus (up to 50%) against the light mounted units in order to break the rock-paper-scissor circle a bit. Otherwise, two armies with about equal strengths and combined forces would never attack and be able to defeat each other (because the cavalry archer would effectively counter and defeat the attacking swordsman), and the game will become dull. With this aid, a combination of archer and swordsman will be able to win battles, which is quite logical.
I think this is a system that AI can handle. The vanilla CIV AI knew when to build swordsman, axeman or spearman. So it "understands" that x is strong against y, but the current system of Realism Invictus is way too complicated with everything having bonus and malus against everything. Some have malus while attacking melee, some have bonus while defending against ranged... So the confused AI always builds the strongest unit available, which is Horsemen, which don't really have any countering units anyway. For example AI wouldn't even build a spearman, because it doens't consider spearman as a countering unit for horsemen. Actually, horsemen gets even bonus against melee units!
---
Alternatively (or additionally), I would recommend an anti-mounted aid provided by spearman, which gives bonus against mounted units and decrease the collateral damage suffered from them. But the AI doesn't understand the aid system yet, so...
---
Maybe you may find it a bit unfair that, the spearman beating a 2-3 times more expensive horsemen. Maybe again additionally, we can modifiy the barracks that it gives 2 XP to mounted and the stable additional 3 XP, so that a newly trained horsemen has the opportunity to get the shock promotion immidiately, which will make the well trained horsemen a dreadful unit. (If someone is ready to invest in those buildings of course)