Hmm I think this AOR and a factions ability of recruiting is an interesting Topic.
If you can "send" units from India to greece, why can't you recruit Scordisci Heavies in Buridava? Why are there some Units you can recruit in far of areas (like Eles in Antiochia or other High tier Makedonian units in Alexandria/Pella/Antiochia/Baktria) but not others?
If Epeirotes can recruit Elephants in greece, why cant the macedons? Why do the Selekids have Babylonian Spearmen but not the Ptolies when they conquer Babylonia?
What determines which faction can recruit which regionals? (I think the diadochoi eg should have the same regionals in the same region. Not sure if thats the case)

I know that we shouldnt enable all units to all factions, but I hope in EBII there will be a higher diversity, especially in the regional roster, contained by a lower replenish rate..