It is what it is now, but Ports relative inaccessability to punters from other suburbs definitely would have restricted its growth and its reach. South had three of the nine official VFA premierships (and 2 of nine in the unofficailly years prior) before the VFL was formed so it would be impossible to not invite them to join as a foundation club.Football wasn't always just governed by catchments.
Collingwood initial catchment was small.
Memberships were always the largest.
2000 members by 1894.
So money dictated some successes, especially with luring country and interstate players.
As said, Port Melbourne access to industry support would have hurt South Melbourne.
The friendly relationship between Souths and Port would have ended.
(Collingwoods catchment might have been small technically but it wasnt enclosed by the bay and the river and the city and hampered by terrible public transport like Port Melbourne is)