I was thinking about this as our formations (4-2-3-1 and 4-3-3) haven't been all that successful so far.

Our problems seem to be primarily getting dominated in the midfield, and so to counter this, a 3-5-2 I think would allow our midfielders to play more narrow with a lot less area to cover defensively. Of course this relies on the wingers being beasts - but luckily we have a couple of those in Valencia and Shaw.

A line up looking something like this

-------------------De Gea-------------
-------Bailly---Smalling---Blind-------
Valencia--Pogba--Fellaini--Herrera--Shaw
------------Rooney---Zlatan----------

Our back 3 there I think is solid - yes Blind is not the fastest, but his positional play is good. Potentially we could swap him out for Shaw and play Martial on the left, but Shaw is quite short for a back 3 I feel. The worry of course, is if one of the payers gets injured we're kind of fucked as we don't necessarily have a lot of depth at CB.

The positioning of Pogba on the right is crucial - this allows him to get forward as Valencia is good cover for him, and Fellaini can defend the center of the midfield physically. Although Fellaini's passing is not the best, it should suffice for that role, with Herrera also available. What it means is that while Pogba still has to defend, it's not quite as critical when he misses out an assignment.

I know the Zlatan-Rooney pairing is slow. Ideally I'd like to see Mkhi partnered with Zlatan or Rooney with Rashford - one with pace, the other can drop a little deeper (almost as a false 10) and supply through balls. Circumstances dictate though that both of them play. If teams play a high line, that provides lots of space for Valencia and Shaw to run into.

I know the 3 at the back is tough to execute well - which is why I'm asking if Mourinho has ever played it. If he has it could be an option for us to provide more cover in our midfield while still involving our attacking players in a meaningful way.

Be interested to hear other people's thoughts on this, I feel like I'm overlooking a glaring weak spot somewhere but can't spot it.