We should not be thinking of alternative positions for the likes of Mykolenko, Barry, Beto, McNeil as they're all garbage and need to be punted from the club asap.
I think we all know the best positions for Grealish (left wing), Ndiaye (either wing), Garner (centre mid). Dewsbury-Hall I'm still not sold on but maybe having real striker would bring out more in him.
Dibling hasn't been given a chance but he's clearly a right winger, which is baffling when we have two superior wingers already and desperately needed strikers and full backs.
Iroegbunam is one who may still need to find a position, but I personally don't think he'll ever be a top or even above average Premier League player - but good to keep around for the next 1-2 years to give him the opportunity as he's certainly doesn't stink the place out when he's on the field.
Alcaraz is clearly a number 10, O'Brien a centre half, Röhl I don't think has the attacking instincts to be higher up the field so likely a long-term Gueye replacement if he can step it up.
Right now it will probably be better if Moyes actually uses his squad to remove the awful strikers and play Dibling and give the excellent Ndiaye a go up top.