Pogba is a bigger talent then Stephan El Shaarawy. Consistency is very important to me when judging a young players abilities as everyone can hit a lucky streak.. We should keep Pogba for a long as possible and then sell him once he sort of pushes for it himself.
Selling Pogba for a huge load of money and reinvesting smart would be fair by me. Look at Roma reinvesting Marquinhos and Lamela sales