We would have more quality if we keep Pjanic and sign Ndombele and Sergej, even if I want Pogba the most of all, the 3rd piece in your scenario with Pogba would be Rabiot, and he is way weaker player then the mentionned options.
But neither scenario will happen because we aint signing two signings that are each worth 70m atleast, especially after we got freebie Ramsey.