However, if a campaign gets boring,
true dat!
tho I think many People like romes playstyle. and the reforms do entertain a bit. Carthage has a good regional roster for their immediate area of Expansion, but further away it's just as good as everyone else's. one Bonus rome has compared to several other civs is that they can train regional elephants. That's really great when you're not carthage.^^

and as said, outside of pretty much their starting territory carthage runns out of factional troops to retrain.

Carthage is more fun and I personally prefer them but Rome just has more "conquer the world" potential. mainly because EB is so historically accurate, and they actually did^^.

I was reffering to classical hopites as good Basic Units for hellenic factions, for carthage and rome it definately is rather off. This also makes KH sort of a candidate, as if you don't want to rely on those dreadfull Reformed hoplites classicals are the way to go, or thureophoroi, but that's to modern for my taste^^ the downsides for the KH are that they lack high Level garrisions and their roster *whispers* suuuuucks, not because they don't have great Units, they do!. but because they lack too many troop types.

AS, yeah, they sort of already expanded^^. an Option would be to subdue all hellens, that's quite some land to conquer. apart from india and Baktria the territories to the east are mostly worthless. conquering the Ptolemaioi and pontians is of greater interest. After that(and the east is secured) you may want to "return" to pella and reunite alexanders empire. expand it to where alexander stopped and spread your rule to the People of India. Or stand up to the upstart Empires in the western mediterranean.