Style I suspect. I don’t know Sheff Weds style. But he isn’t a back-to-goal striker that thrives off slow build up.
If Wednesday play with a quick counter attack and ball through the middle, or wingers who get wide early, beat their man and whip it in quick, or target man flicking it on behind in a 4-4-2, 3-5-2 with Ugbo running behind, then Ugbo would thrive.
Bulut’s attacks tend to be big set pieces, or the ball out wide (rarely put behind down the middle quickly). In a 4-5-1 no second runner behind with legs with flick ons so we rarely see that. So Ugbo would struggle.
So I am guessing style.