You think so? I dunno. Even if he can only last 60 minutes that would still be very valuable.
Btw he has played as a wingback a few times and was great there, didn't have particular issues with stamina either
United's biggest problem is your midfielders can't bring the ball forward reliably, so you have to rely on Shaw on Maguire to do that, or Bruno/Pogba/Etc have to drop deeper. Wan Bissaka offers nothing in this regard either. Adama basically can't be pressed, and can get past the first line of defence quickly and consistently.
On a great team i think he'd be a cheat code in build up. Theo at milan is similar, and adama is even faster and stronger and a much superior dribbler. And in attack he's a much bigger threat out wide than people give him credit for. Again, his underlying numbers are really good compared to wingbacks. His final ball is pretty good actually. Just teach him to make off ball runs