Without Niall Quinn I'm not sure who will stop him at Sunderland. He gets average teams into the Europa League places for a couple of seasons then leaves behind an almighty mess when it turns out he can't take the team any further (Champions League, cup wins). I don't rate him at all and was very relieved when the board went for Harry and put him on a tight leash with a strict wage structure and spending limits. I'm not sure O'Neil could succeed at a club like Spurs or Arsenal where the club must make a profit to ensure continued success and investment on the pitch.
You've just described Harry Redknapp at Portsmouth.