It's a tough one to be honest. It has to be viewed from all angles, and I'll preface this by saying that Pep is my favorite manager in world football. I love his brand of football and he's been my favorite since SAF retired.
By and large, his football has worked everywhere he's went, and he's been successful with it everywhere he's went, including breaking the points record in English football. I'm not a big fan of 'pragmatic' managers. For me football is about entertainment first and results second. A manager that goes out there and tries to win the match on his terms, playing his football, regardless of the opposition, will always be someone I support more than someone that changes on a game by game basis to adapt to the opposition, without having a clear defined idea of what their team should be. Pep most likely would have won more had he been more willing to compromise his ideals, but you know what, I can't fault him for that.
With our squad as it is now, I can't say. Our squad isn't built for possession football, as we haven't had a possession based manager since Vangle, so it's a difficult question to answer since our squad was constructed differently. I have no doubt he would improve our players, and the football would be much more entertaining than it is now, but as to how good we would be, it's impossible to say.
On the other hand, this crop of players would win the league under Klopp. I am convinced of that.