West ham, swansea, leicester, basel, everton, burton albion, CSKA and Crystal palace... None of those are very tough games. Of course we had an impressive start to the season, but you can't say because it worked then with Pogba that it's the way to go. Also using an argument like "it worked for a brief time at the beginning of the season therefore never needs to be changed" is one of the worst arguments. If our whole form depends on Pogba being on the pitch, then it's not exactly a working system, it's more just 1 brilliant players elevating those around him.
Also I don't understand this at all. What do you mean what then? What, then you don't have the option of potentially trying this in the future because it wouldn't have worked the one time (as if it's working right now)? What we know is that right now, our main threat is always either Martial or Rashford. Whichever of the 2 is on the pitch, we pretty much always look to them (and just them) for any cutting edge. Our #10's do nothing, our right winger does nothing. Lukaku does alright but isn't someone who can create for himself or others. Are they both probably better on the left wing then the right? Yeah, could be. Especially martial. Doesn't mean we can't try to play Rashford on the right. He sure as feck won't do worse then Mata or Mkhitaryan's non existent performances out there. And it's not like either of those 2 are good defensively, so in the end, it's only positive for us. Mourinho has his reason for why he has it the way it is, but whatever they are, I don't see the logic in them at all. Rashford and Martial can play together on the wings and you can bet your ass that if we had a more attacking manager, that he'd play them both together from the start instead of going so conservative and worrying about keeping a solid defensive set up every game.