On the geography front, I always thought using the Yarra as the split would've made sense, it runs right past AAMI park, so makes the use of the stadium for both teams make sense as well.
Heart needed to put a training facility in on the south side of the river. Of course setting up that identity for the team now is just too hard. It needed to be called South Melbourne Heart in the beginning or South Melbourne FC, now probably just too difficult.