I'm actually really surprised he became a full-back, at school he was very skillful and tended to play on the wing, I guess the youth coaches at Rangers didn't think he was good enough for the wing at pro-level and but saw something in him defensively which meant he was kept on as RB.
I think we see that in his game, IMO he's excellent going forward, not unlike Walker but with less of an engine, but he's prone to errors and lack of concentration at the back which at English Prem level, you get caught out.