Well I agree. Some paradox games also have this problem: of course this game should be realistic -and we're here because we want it as realistic as possible-, but that does not mean that it should be fixed in every way. If you know Carthage will attack in 272 bC by event, you'll be preparing for war years before that. What you want in this game is to be uncertain -to a certain extent- who will attack you. You should see some armies massing one year before they do, of course, but there is no blitzkrieg of surprise.
So I agree with Mogan that if you make the set-up really balanced (even if that is a bit more unhistorical), the random generated outcome of battles may be different, and every game will play out different, making it interesting for the player. What this mod adds (to me it seems at least) is historical accuracy, not historical determinism.