When has he last used a pure midfield enforcer? He seems to favour a someone who can ping the ball around, at least since he moved Pirlo from attacking midfielder back.
And I don't criticize Sidibe but he would need to play a game alien to him if he stayed back while Digne bombs forward.
It's a good question, and hard to say, because the last...4 teams prior to Bayern didn't use one (they didn't need to). That said, I'm no expert on him; I only saw him play maybe 3 matches last year, but I checked real quick on whoscored and Gbamin's passing is excellent, both high volume and completion %. Plus I don't think he's just an enforcer. He's like Gana-lite and even joins the attack when warranted (2 goals last year). It can work IMO!