He doesn't work as a left winger for us.
One would expect him to emulate Mahrez because of their style, slightly slower but better on the ball wingers.
But Mahrez is much more dynamic while Grealish plays it safe, perhaps under instruction, he does help us keep the ball better. It's a bit odd because at England he seemed way more in tune with going at his man.
I think his natural position is midfield, he seems to fade out wide where he isn't the center of play, but we have 3 other phenomenal players there so no time.