Well, honestly, in terms of pure vision and creativity on the ball, Pogba over Thiago. But in terms of all round game and the ability to keep the ball ticking, Thiago any day. Compare it to a Xavi and Iniesta combination. You can technically play both of them together in the same team, with Pogba being the more dynamic midfielder forging ahead, while Thiago pings the ball and keeps circulating passes. Of course, also necessitates that you need a Biscuits behind them to bring out the best of both of them, so yeah//The difference between Thiago and Pogba is he's more consistent plus he's the better press resistant player. Against a high pressing team, I'd play Thiago 10 times out of 10 over Pogba. I can't count how many times Pogba has gotten dispossessed in his own half for dallying on the ball for too long.
With Thiago, you get a player who has the guile and technical ability to beat a good press. I watched him alot at Bayern last season and he is soo good with his back to goal when pressed.