Would love to do a campaign with Koinon Hellenon but would like some more help.

1) What is the typlical battle roster for a Koinon Hellenon 20slots?(Sort of a composition of a legion or so although its different)
2) If I would try to re-write history what would I try to do and where would I try to go?
3)Are there any reforms with Koinon Hellenon? and how do they kick in?

And more info please.

Thanks
Etienne