Willock is a box-to-box midfielder, or an '8' in modern parlance, and could do a Ramsey-style attacking midfielder/second striker role because of his powerful running ahead of the ball. Played 10 a lot as a youth, as Claude says, but perhaps lacks the finesse there for top level football.
Smith-Rowe is more versatile. He played the majority of his youth football wide, especially on the left hand side; he did a good impression of Bobby Pires when he played for the U18s. But was then used more and more in the classic 10 role for Arsenal and England, until last pre-season, when Emery started playing him in that 8 role quite a similar progession positionally, albeit abridged, to that of Kevin de Bruyne. And similarly to the Belgium, I'd say right now he's best somewhere between an 8 and 10.
