Even though Real socidad is seen as the favorite team here, what will justify that is the full time result and the last time I checked statistics it was only once Real socidad has won Manchester united and they draw 2 and Manchester united won 3 so there is every possibility that Manchester united will or can win the match regardless of there current performance because history is always hard to change and I observed that Manchester united has not lost against Real socidad from away in there last five matches, the bookmark make it look like Manchester united will lose the game but those are manipulation.
If you are waiting for the final result to determine who is a favorite, the context is not a gambler. We are analyzing for predictions who will win or how the results are with the statistics that exist in both.
I doubt Manchester United, which continues to decline even though in UEFA Europe, Manchester United's performance is quite good. If the results of the analysis are more possible, then I might also have a chance to bet on these results.
Honestly Sociedad isn't the type of powerhouse that would destroy United neither, not even when United is doing this badly. So everyone has a question on their mind and I can understand why, we should be considering this as a risky move and should not be an easy bet.
I am not saying you should bet on this or that, I can't make that decision for you, but I am just saying that it is normal for people to have a confusion at this point and not know what they should do, because it's normal not knowing if you should be betting on one side or another. I have seen people betting on over/under JUST because they couldn't decide on which team will win, and this looks like exactly that type of game, makes more sense to bet on the goals scored.