But Masche is actually a starter for us while Yaya would not have been one.
Would it have been insane to play a different formation, had Yaya Toure played in a 4-man midfield + Messi as False 9?
Imagine that Ibrahimovic never came and we sold Eto'o. And Pep's tactical vision made me play with 4 midfielders (Busquets, Yaya, Xavi, Iniesta), with Messi playing perhaps more to the left off center, with Iniesta acting as a sort of wide midfield playmaker and Alves providing the width on the right side, but with more CMs to work with instead of an overlapping winger/wide forward. And we could have even tried playing Messi in a more advanced free role with him freely drifting into midfield or not, with Yaya as an attacking pivot. He did that job admirably at City, no reason he couldn't do it at Barca with much, much better support through Xavi, Iniesta, Busquets, while feeding and receiving the support of the best player ever in Messi.
Yaya back then is like Pogba matured into a world-class midfielder with even more power, perhaps less refined technique.