So I presume you're also giving Ferguson no credit for his work with 'the class of 92'? He deserves no credit for his role in integrating them into the team and developing them as players, putting faith in them?
For one, you have to consider he was letting players like Ronaldinho, Deco and Yaya Toure leave/on the bench. He had money to spend and more experienced options, but he put faith in someone like Busquets. There's a lot of revisionism that goes on with the Barcelona squad he inherited, where people look at Xavi, Iniesta, Busquets, Pedro, Pique etc and say that team was the one of the world's greatest, but no one was saying that at the time. If Pique was such a huge talent destined for greatness why did United let him go for 5m? I'm pretty certain Real Madrid were the bookmakers favourite to win La Liga the season he took over, and Barcelona would not have been favourites for the CL either. Also, if you watch the Barcelona sides under him and can't see the influence he had on the team then you must be blind, there's a reason he's one of the most esteemed managers in the game, and people like Ferguson who rate him so highly, have a better idea of the work he does than me or you.