The first thing that's stopping me is that I'm already involved with making a mod, and the second is tht neither one of the two games would be near adequate to model Ancient Egypt.
Starting a project that is likely to fail due to their being an obviously better game for the job is also "extremely unhelpful". Would you prefer he and possibly his team burnt out sooner or later? How many big mods for games have you seen succeed or fail? Better advice may perhaps be, start on something a bit smaller, get to know each paradox game then if you're still sure this era and that ck2 is the right game for it in a couple of months time (or 20 hours of playing around with the files, whichever one comes sooner) then begin. If not... then learning the ck2 engine in the mean time by making smaller mods is one smaller step to take before making a bigger one.
I'd rather hope you know what you're actually talking about before accusing me of being "extremely unhelpful" thankyou very much.
And Victoria 2 has (up to 8) slots for greater powers and (up to 8) slots for secondary powers. I'm aware it'd be more than those 3, but it can be any number people want with any modifiers making influence easier to gain based on whatever conditions the mod creators want(how much more influence points should the major cities/powers get for being bigger?). Point being that sortof system is very much in place for victoria 2 and not even remotely for ck2. You can make certain events trigger or not based purely on whose sphere you're in as well, like for instance perhaps people in the athenian sphere get an income bonus but the spartan ones get a military bonus (or to give a slightly more esoteric bonus, a bonus for stability when your cities slaves revolt). You can also rig the greater powers system with events if you rig it via prestige.The ancient greek world was more multi-polar then just Athens and Sparta. Those states were perhaps the strongest but even they were eventually bested by Syracuse and Thebes respectively. Even beyond strength lies the fact that hegemony in the greek war was about more then which state would best the other. The war was more indirect, with things like who's ally would deplace which village being essential.
This thread was posted in the March of the Eagles forum, but was moved here. I assume because of the CK2 screenshot showing what the map would include...
I suggest you help Ataulf instead with this Mare Nostra: Rise of Rome mod, since its larger and also cover the Pelponessean War