Ah, it's optimistic Puzz3D again.. havent seen a 'i love RomeTW' post from you yet :)
Now since we dont know the engine formulas, how can you say that the effect in STW/MTW is more pronounced than in RTW? Also, they DID try to balance RomeTW, and it is pretty balanced stat wise, but game mechanics like cavalry charging proved to have a too large effect on things.

In my opinion, swords and spears are better balanced than in say, MTW. Also the cavalry in RTW behaves a lot more realistically than cavalry in STW, which was basically just treated like a somewhat faster moving infantry unit (ie, units locking together in hand to hand quite boringly, not happening very much after the charge except a drudgematch). Anyone playing STW and MTW can verify this. And you could not really withdraw your men from melee, but in Rome TW, you can.