I rate Frank, no denying that promoting Brentford and keeping them there, shows he knows what he's doing.
Why he will succeed: he's pragmatic, has a cool head on his shoulders and is tactically good. Also seems like a real people person. He's also patient with players; like Damsgaard, it took a long time to get him going, but has shown last season why he was one of the first in the team selections. Many mangers would not have had the patience, so he has the "players will run through a wall for him" thing going. He has a great set of hair as well!
Why he will fail: he' needs time to implement his ways. I remember seeing an interview where after the first two seasons, he got a call from Bennham, expecting to get fired, since the results were not great, but was told to keep going as the numbers look good and they were moving forward. Patience is not what Levy is all about. But to be fair, unless he gets us relegated, the season could not have gone much worse, and I will still say that had we not met Manure, any other team would've gutted us.
Also he has great hair, Levy will be jealous.