In as much as Erik Ten Hang didn't have a nice season, it doesn't make coaches like Xavi Hernandez and Thomas Tuchel better than him. If I am among Manchester United management, I cannot any of the above coaches above Erik Ten Hang.
Certainly, it seems Manchester United is not interested in dismissing their current coach. They might have concluded to give him one more season and make available players for him to try again this season. I personally believe that Erik would have done better if there were available players for him throughout the season. For the majority of the season he played without good defense, to the extent that Casemiro was occasionally made to play defense.
If we talk about statistics, Xavi and Tuchel are the two best coaches compared to Ten Hag who only won the FA Cup title. Here are the third statistics in 4 different competitions for each coach:
Source:
https://www.transfermarkt.com/- Xavi recorded 53 matches this season with 35 wins, 8 draws, 10 losses. (La Liga, Champions League, Copa Del Rey, Super Copa).
- Tuchel 49 matches with 31 wins, 6 draws, 12 losses. (Bundesliga, Champions League, DFB Pokal, DFL Supercup).
- Ten Hag had 52 matches with 26 wins, 7 draws and 19 losses. (Premier League, Champions League, FA Cup, EFL Cup).
Xavi and Tuchel both succeeded in getting their teams to qualify for the Champions League next season even though both had to face the fact that they were fired by their respective teams. Ten Hag is not better than the other two coaches you want to compare, but Ten Hag was lucky to beat Manchester City in the FA Cup final this season. I'm talking facts about all three coaches, so I don't think Ten Hag is better.