That should be the plan, yes. However, my problem with that plan would be that it does not solve one of the biggest problems with the current United squad: the dependency on Carrick.
Thiago+Carrick would be in my eyes the only working combination, because Carrick is the only current CM, who is defensively strong enough to truly watch Thiago´s back.
From what I´ve seen from Thiago, he is an AM/CM hybrid with a clear orientation to be offensive. He does leave some quite big holes behind him. The best possible partner for Thiago in the CM would be a classic destroyer like for example Sven Bender or Luiz Gustavo. No one in the current United squad qualifies for such a role, though.
On the other hand, Thiago is still bloody young and under a good coach he could develop enough defensive attributes to become a wellrounded CM.
We are signing Thiago to play together with Carrick. The other combination could be Fletcher + Thiago if Carrick is injured and Fletcher is fit, but surely we are not getting Thiago as a possible cover for Carrick. With or without Thiago, if Carrick is injured we are pretty much screwed.
While it can work, Carrick + a defensive midfielder, I don't think that is the best scenario. Bayern did that fine, but I don't think that Carrick is as good as Schweini in that position. Carrick best position is playing as the least advanced midfielder for us, when he does the defensive job very good, but he can also dictate the game. Having another player similar to him would be dull IMO, personally I never liked Carrick-Fletcher combo because they were very unattractive. Though of course, in the big matches away we probably should play a more defensive player with Carrick, but in majority of them there is no need for it.
Thiago is goo defensively, 33 minutes for a tackle and 38 minutes for an interception are good numbers IMO. He is not like Anderson when he came for us, even in Barca the position he plays is similar to the position he'll play in our midfield (though there are different tactics and formations).
He is one.
'If he plays where Kagawa plays, why are we getting him when we already have Rooney and Kagawa?' Put two and two together, ffs. He doesn't play where Kagawa plays, hence why we're after him. He plays where Cleverley or Anderson plays. Makes more sense now?
It's amazing how people say that he'll play in the hole, or that he's an offensive midfielder (trequartista, whatever). The last player Barca played in the hole was, well... I don't remember and surely we must go more than a decade back in time to find him.
Pretty much is, well he's young and a good dribbler, so he plays in hole.