According to the description posted on the Total War wiki, Macedon is a pretty organised place, "an administration, with the king holding power and governing in the name of the people." The Macedonians make their money through trade and agriculture and field strong armies of horses and cavalry. They don't get along so great with other Greek states, though, because their neighbours view their "hegemonic tendencies" with suspicion.
It looks like this successor state is a faction better suited to players who are inclined to go it alone, as it's both economically and militarily strong, only relying on its subjects for sea power. Macedonian warriors are strong against barbarians and the faction enjoys bonuses to both trade and population happiness. That speaks of stability and security, exactly the sort of faction you'd want to be but, with that military might, not so much the sort of people you'd want camped next door.