Manchester United will not win, Amorim will do new experiment again.
Everton have a good defense, Manchester United will not able to break it since their attacking line isn't sharp. Manchester United should be grateful if they not lose, you know Bodo/Glimt in Europa League almost beat Manchester United, while Everton is two or three times better than Bodo/Glimt.
Every game is usually difficult and it is been played with a different approach and mentality. Everton hasn't been very good this season and I don't see what they are playing that's making you think that Manchester United will not beat them. One thing I like about Manchester United is that, they may struggle with small team but once they face an average team or bigger club they give their best and surprises everyone who has been doubting them. Take it from me that Manchester United will defeat Everton when they meet. Everton is not stronger than Manchester United, Amorim has recorded a draw in his first game and he won't allow that to happen again and he won't settle for anything less than a win in order to maintain a good relationship with the fans of old Trafford.
Man United is indeed still adapting to their new strategy, and Amorim may still carry out more experiments, but I guess it will only be focused on the back line and the flange. Meanwhile, on the front line, it seems he will not make any changes because that line is currently quite productive, and I think they will score again against Everton. If Amorim can find a good composition at the back, I think they will get the win.