I have to agree with GGyid, it has no relevance. What Guardiola has brought tactically, which was what your original question concerned, is an incredible detail which manifests itself in not only game-to-game and in-game tactical tweaks, but in the evolution of the squad to keep things fresh as well. In 2009 They had Eto'o through the middle, Henry left, Messi right in a fairly standard 4-3-3 with inverted wingers. The next year Ibrahimovic came in and Messi started to play through the centre as a false nine. Last season Messi was a permenant fixture in the centre and Barca used a back three often including a midfielder allowing Alves to be unleashed down the right. Now we have seen the introduction of Fabregasto the squad has allowed the tweaking of the team to include a ridiculous amount of ballplayers, as we saw against Santos in the CWC Final, with Fabregas and Messi forming some sort of bizarre fluid front 2, along with a variety of past tactics. He has kept things fresh and built up a strong collection of systems that the squad are comfortable with.
Although I do think there is a lot to say for his impact on their playing style. You can only play like that and win through utter dominance and commitment. That comes from training and tactical knowledge, striking the perfect balance to get the best out of the players, and that perfect balance is very hard to find especially for such an extended period. The fact that so many players have come in and out is testament to the ability of Guardiola's ability to impose his tactics regardless of his personnel at Barca.