I think Newcastle and Aston Villa will also be among the teams that can get past Manchester United. It seems to me that you are very positive about Man Utd, because they have not had so many changes in the off-season to expect that they will become stronger. I know that everyone wants to believe that this is possible, but I think that they will not be able to compete for the Champions League this season, at best it will be the Eurocup zone.
The good news is that they are putting in efforts to revive the team and bring it up to standard this summer, they have made some important attacking signings and still working on signings in the midfield and a defender hopefully so it is work in progress for now. Hopefully they will be good and strong enough to compete with Newcastle, Aston Villa and the rest of the EPL teams for top four in the coming season.
They are doing it very slow (just three players) and very expensive (225 million so far) when they are doing that, and not even getting any stars while doing it. Like spending 75 million on Sesko makes no sense, I am 100% sure that Sesko will not play like a player who deserves all that money. They overspent on all players, and the season will show. When the season starts, well not even starts, when it ends, you will see the stats, and you will ask yourself, "did these players really worth 225 million for what they contribute this season"?
Because you really need some star level players to get this team better, and if you are ok with spending 225 million, you can get 2 star players instead. Or if you think the whole team sucks, sell all players for 10-20 million whatever, and get 10 new players and rebuild.