In fact, Sancho return would be very welcome considering that he is young player who has quite lot of potential, but for now because the team doesn't have much support for him to play well, his performance as an attacking player looks less sharp.
Sancho return from Dortmund is good opportunity for Manchester United to build much better strength than last season, Ten Hag was too reckless in borrowing or selling players and he should have been able to retain his players after completing the loan.
However, while Ten Hag was coach of Manchester United, he always made several decisions that were quite ridiculous and were considered detrimental to the team. Hopefully, if he stays as coach, he won't make any more mistakes in the future.
You are right, after all Mainoo is still very young and he can be trained and developed into great player, plus his performance as player can also be considered not so bad.
If the use of players can be really appropriate and in training sessions can optimize performance well, there is big possibility that Manchester United can become strong team like before.
Jardon Sancho, one of United's best signee months back has now become a least option for clubs even in United itself. Sancho himself started derailing in his performances so it's difficult for teams to be confident about buying him and keeping him for years in the team. Also coupled with his issues with the coach. A team doesn't want for themselves, a player that's drawn back in his game play, yes for United, their best option would be to sell him but for other teams, first they'll reconsider purchasing him before considering his rate.
He just needs extra work on himself, Manchester United may not do the trick for him that's why he really needs a change of team but at thesame time, ths options just have to be weighed and decided rightly before concluding. United's Sancho really has been set to exit the club in the last January transfer window. Hag didn't seem to have a use for him and him still being there only made him less active and it affected his form. He's a young star, yes Manchester United enjoyed him during his playing time but currently, he had not much to do for the team so it was just best he exited the team.
Although it was rumoured that Juventus must have had an interest, well they're not a bad team, they take part in the UCL too and definitely he'd get to have a spot to show off his talents. Now is not the time to sideline stars, everyone needs to make themselves relevant and build up a good name too.
Without doubt, Mainoo is a good impact to the Manchester side too. Yes, much was expected from Sancho but since his delivery rate was a bit shaky, twas fair that they set him out to another team. Having him back would be good but it'll be a decider as to the fate of Mainoo as well. The coach would have to work with the both players.