I don't think it has anything to do with being old scholars or whether or not you pay players. To me its far more critical that players get along at a club and socialise together But this is the exact point!
If you're an old scholars club, there is a reasonable chance that a lot of the players have known eachother for a long time, gone to school together, or at least socialised together outside of footy for a long time.
If you're a mercenary club that recruits players who are there for money, this wouldn't be the case - or at least not to the same degree, which might not cause divisions or mutiny or anything like that, I am sure they're still good people, but in cut throat finals, playing for your mates that you've known since year 9, counts for a bit.
Personally speaking, I played for a team in Victoria that paid players, I was one of them, and it was different. Everyone was friendly enough towards each other but it definitely wasnt a group of mates playing together.
It's a factor come finals time IMO and might go some way to explaining CLG choking against WOS all the time.
The case in point is WOS vs North Haven, as Dragons says being old scholars has nothing to do with it and in my opinon being a close group is only part of it.
North Haven had 21 players of 22 in that game live with in a few kilometres of our club, most went to school together, played juniors together or are close friends in many cases all three. Add to that 3 sets of brothers and a father was assistant coach. I have never got along with a football team as much as I have with this one.
Yet we got comprehensively beaten by a team who was in good form, finals hardened and had an excellent game plan that was executed perfectly.