Same, and even that's not a guarantee IMO. He's only 18 and barely has the equivalent of 3 full games of professional experience. Look at Rashford and how long it took him to come to terms with professional football. Look at Greenwood who was even more impressive and how much more difficult he had it in the first half of this season. It would be deeply unfair to put all that burden on Diallo, and we need a RW in any case, even if it isn't Sancho.
The need at RW is the same as it is at DM, for me. Even just getting an above average specialist in that position would do wonders for us, but getting the creme de la creme there would have us punching very near the top on its own.