Really? I don't watch Thiago every week, but anytime I've seen him, he's been largely superb. Also, what's wrong with that, nothing wrong with a flair player. I thought Man Utd liked their swashbuckling players?
Of course there's nothing wrong with having a flair player around, except when he's too much strolling around, in places where you better not joke around and not cutting out the flicks and 'hollywood-passes'. The (first) game where it mattered most against Atletico was the same old Thiago, IMO. He reminds me of Fabregas, meaning he has it in him to play that one pass that cuts the whole defensive wide open, but football isn't all that. He leaves his team open for counter attacks, more or less similar strengths and weaknesses as the aforementioned Cule.
Bayern have an incredible block of strong defensive players; In their midfield, Alonso still has great awareness and Vidal is a no-bullshit player. So he's well protected! Moreover it's easier to get away with a player such as Thiago in the Bundesliga than in the Premier-League, IMO.
I love Pogba and think that he is great and will become fantastic, but bar being stronger and having a slightly better shoot, Thiago is better than Pogba in pretty much everything. Passing, dribbling, reading the game, defensive contribution are all categories when Thiago is better than Pogba.
Expectation wise Pogba could have been better. Sure! But that doesn't make him the lesser player than Thiago, IMO.
Thiago edges Pogba when comparing their respective dribbling capabilities, but apart from that? Pogba plays also magnificent long balls, both of their short-passing is still flawed. If i were you i wouldn't underestimate the fact that Pogba has much better athleticism and with his body, his defensive contribution is in no-way any less then Thiagos'. Pogba isn't as naive as Thiago when it comes to losing the ball in dangerous areas. So, has Thiago really a better reading of the game?
Personally, i'd take Pogba more serious as a leader on the pitch. I think he actually tries, whereas with Thiago i'm not sure whether or not he'll give his all. During his final season Guardiola left him out from time to time and that's because he lost a bit of his trust, IMO.
Maybe in other countries it would be more close (doubt that), but for the Premier-League i think Pogba is the much better fit.
FWIW, our current team is completely built around him. There are 3 players we cannot afford to lose without suffering an immediate drop in quality: Neuer, Thiago and Lewandowski.
I know that Thiago can be outstanding with the ball at his feed, but personally i'd held Vidal in much higher regards than Thiago. I've seen how Ribery destroyed Schalke in the cup recently, i think he's still so important for your team and Robben has been playing quite well so far. Coman and especially Costa ain't all of that, IMO.
All players i'd take ahead of Thiago.