Rassie, I have never seen any (halfway decent) referee from either hemisphere be "more strict on the attacking team". The team in possession almost always gets the benefit of the doubt, at least as long as they do nothing egregious.
But to return to the OP, in SH (i.e. Oz) it is not uncommon to pick 15 all-round rugby players, whereas in Europe it is considered normal to pick props to play at prop. And props to score tries
When both teams are playing to the same hymn-sheet, it doesn't really matter what the referee does, in terms of the final result.
When the two teams play very differently, they may notice a difference. If suddenly refereed by a guy who knows what a scrum is, against a team with a decent pack, yeah.
There is a reason that all the best SH refs are Saffers.