I don't understand the problem with Ralf Rangnick. He didn't use Mata until the last few games of the season. He noticed we have been struggling and yet he won't even explore with other players on the bench. He isn't a good coach in my opinion because he doesn't know how to use certain players and protect them with other players.
As for Southgate, I've never liked him. His selections are always off for me. He picks based on sentiments.