Personally, I think Leroy has suffered because of Mendy. (I know he’s been injured, but hear me out). Without Mendy, Leroy has been able to hug the touch line and cut in usually behind the full back to latch onto David Silva’s passes. Zinchenko is perfect for this as he generally cuts infield whereas when Mendy plays he invariably moves to the touch line to whip in his crosses. The other side is similar in that Walker is more of a touch line hugger and Danilo likes to cut inside. If you look at Sterling on the left, he prefers to cut in, leaving Mendy to do what he’s good at. I’ve noticed that the times when Mendy and Leroy have both played that there is a stutter on hat side as they both seem to not anticipate what the other is going to do. The left hand side is, I think, where we get most of our crosses and tap-ins, so is a very important part of our play. Maybe I’m wrong, but that is what it has looked like for me...( apologies for lack of paragraphing, but I only got a CSE Grade 4 at school for English. Not one of my strong subjects!!)
I get your logic however I think they only started 3 games this season together. 5-0 Burnley, 6-1 Southampton and 3-1 Palace. If you take the Palace game you will notice Mendy playing inside most of the time with Sane wide left.
I personally don't think Sané's lack of game time has anything to do with Mendy.