Yea, I think Tuchel would have done much better. Pointing to the fact that Chelsea lost a match under Tuchel as some kind of evidence that he wouldn't have is a pretty weak argument. Literally every manager has lost a game against a weaker side, including Pep, Klopp and all the great managers of years gone by. I assume you don't think none of them couldn't have done any better than Ole?
I think Ole's pretty useless and when he's eventually sacked by Utd (hopefully not too soon), not only can't I see him ever managing a top side again, I don't even think another PL side would go near him.
Some people will point to his 'success' in getting Utd back on track and into the CL in back to back seasons but give me a £900m squad and I'd be confident of doing that too, especially since Spurs and Arsenal have been useless for the past few seasons. Just like Ole, I wouldn't need to have a clue because when you're going into 90% of games with a far better squad than the opposition, that alone will be enough more often than not. Unfortunately for Utd, 'more often than not' isn't going to be enough to win a League title when you're competing with 3 potential 90+ point teams. And as Ole has shown, even against inferior sides, you're likely to come up short in Cup competitions too, particularly in the latter stages when the quality of side gets better and have a decent manager.
Thankfully, from a Liverpool supporters point of view, Utd seemingly don't want to make a change unless they absolutely have to and the state of the League right now (the decline of Spurs & Arsenal meaning there's little threat to the top 4) means that it's very difficult to see things going so bad that Utd are forced into a change anytime soon.