I dont think anybody expects him to be the finished article at 19. I feel however, that he has very specific strenghts (dribbling, progressing play) but also very specific weaknesses ( strenght, speed, positional awareness). And I wonder, below the line if the good outweighs the bad. To back this up, apart from the semi final, Mainoo hasn't been on the pitch for a single England goal this Euro's, but he was on the pitch for Slovakia, Swiss and Spain taking the lead. He was also part of the United midfield that got destroyed in the PL past season. Very anecdotal evidence, I know, and hopefully the latter will be different next season.