Jay hasn't played right back, but he hadn't played midfield until he got in the 1st team. By far and away his best position is centre back.
I agree that Williams is a centre back firstly and foremostly .
However , I think the worry is his physical size and strength at an early age in this division , particularly with regards to winning balls in the air.
Don’t misunderstand me though , it’s something to build on and a lot of it is timing . However it’s a danger when you are up against it performance wise