I'm pretty sure he's very much a wing-back as opposed to a full back. IIRC, his debut was against Ipswich which was, I think, the last time we played three at the back with wing backs and also the last time I can remember the team playing with any sort of cohesion. Fleming looked good on his debut, but since then Robinson inexplicably opted to revert to a back four and his form suffered (it also can't be easy coming in on loan to a club in as much of a mess as we are/were). I'm, therefore, inclined to give him another go in his preferred position.
Moreover, I just don't think the Brannagan/McGuane/Bate midfield works. They're all technically good footballers, but the balance just isn't right and it's too lightweight and nice. For that reason I'd rather sacrifice one of them and bulk out the defence a bit more. And, as much as he's a tidy player, I think Bate would get completely overran in a midfield two.