Ruud Van Nistelrooy definitely managed to do the best, and if he can keep this team at the league and away from relegation, I am pretty sure he will be offered a better role in some other team. I honestly believed that they won't be doing that great, I didn't expect a win, and I also believed that Ruud should have stayed at United as an assistant manager for Amorim as well, because he knows United, he is very well versed with teams staff, and players, and could have been a better position for him.
When he left, I thought that was a bad decision for him because I believed he wouldn't find a good job, and when he accepted Leicester job, I said that was a bad move too, because it looked like he would just lose most games and be sad, but turns out, I was wrong and he is doing fine right now. I assume that he won't be able to win majority of the games, but as long as he wins enough to stay around where they are, and not relegate, he will be seen as a saviour for the club.