You can only beat who is in front of you that much is true, however they don't have enough up top and that will see them burn in the later rounds. That is Ibrahimovic at his best barring the days when the ball just falls to his feet. Around him they have a void of goal minded mids and wingers, Pogba gets the odd 30 yard worldy for his youtube highlights and Mata the odd underdog feelgood factor when he grabs the odd one, that is it really.
In my opinion it all depends if the cold reality of the prem hits them with a tougher nut to crack in West Ham or if they bend over. In terms of fear factor now they are like spurs lite, all that 'beat before they kicked off' stuff is null and void now and has been for some time.
They are right where we were 6 years ago with less strategy and a weak business model which will see them stagnate more and that is just fine with me :-)
My long term wish is Mourinho stays and they stay looking up at cl spots with a dearth of young talent and only them eeking every penny from deals gets them washed up has beens on sickening deals. No serious player will look at them as they are a short term money machine and if they can stay like this at 7th the owners are happy. Basically them carrying on just as they are right now suits me just fine.