Not sure if its been mentioned but people often forget the power of reputation in the outcome of matches on Fm2011. Firstly if you have dominated club football for 3 or 4 seasons, teams will start lining up against you differently. Where as before they might have played open attacking football, now they will park the bus and just rely of counter attacks, they will using stand off tactics with hard tackling and just try to bully your players into submission.
Secondly your own players mentalities are also affected. In my current Ajax save I won the CL last season and wasnt even tipped to qualify past the group stage, we beat Madrid in the final 3-1 and totally dominated them. But cause we were such outsiders it was easy to motivate my players, lots of press conferences I said it would be 'a tough ask to win' and then just told them to enjoy the match. We were always ranked outsiders, where as this season we are expected to beat teams who are technically better than me, which drastically changes the whole dynamic of team talks, fan expectation and so on.
So yes in a way success does bring handicaps of sorts, but not the scripted unfair sort. You just have to adapt you play style and approach to the game.