Yeah I thought what I meant was obvious but I'll try to make it clearer
He must take the credit of course for finding the perfect way to utilise Messi (although let's be honest, he's good everywhere), for promoting players from the cantera, for taking advantage of the fact that they had been playing possession football since they were young, etc. These are no small feats. But people seem to credit him with creating this high pressing, possession based tiki-taka football that Barcelona are now known for, when this philosophy had been present at the club at all levels for years. Most of the players he started had already had years to gel as well (again, he knew this and that's why he selected them).
As for Mourinho and "after that he was not exactly given chopped liver to work with". Well, no he wasn't, but like I said above it was on merit because he won the Champions League with Porto, and he was also given the Porto job because he did well with Leiria.