I understand your point, but one thing you most understand is Manchester united performance seems quite unstable.
I did not write that Manchester United have stable performances.
However, other teams might have poor performance in the early stage but before you know it they would start picking up again, just like as you mentioned Chelsea because they were totally not in good condition at the early stage of last season, but just before the end they were able to achieved a top four position, which is quite impressive.
Again if you read my post rightly, you can understand it differently and comment differently too.
Chelsea recovery actually began two seasons ago with Pochettino, not only in the last season and my post implied about that. In the last season, there was weeks Chelsea had troubles but their recovery already started one season before that, and they already had good foundation for better recovery last season. This is not what Manchester United have in this season and they are working hard to achieve this.
But Manchester united was in poor performance from the beginning to the end, even though they have start again this new season and before you know it they might likely continue like this till the end of the season, which is very wrong at least they would have started the new season with more winning ways.
Rome wasn't built in one day and Manchester United must build up their squad and success season by season, and this season can be a start for this successful development but it actually began in second half of the past season when Ruben Amorim left Sporting Lisbon and joined them since winter transfer season.