Toon, Everton, La Arse and Juve have all be linked.
Why do you limit a worse passer to 10 years? Are you 12 or something? Smalling is certainly not the worst defender the club has had and its history is well over a century, so try not to limit the entirety of the club to how long you've spectated from the sofa. If Bruno had the same pass rate if he played in defence, then yes he'd not be a very reliable defender. As he doesn't play there it is a strange comparison, like comparing a strikers shot conversion rate to a keep who once ventured into the opposing area, had 1 shot and scored.
Graeme Hogg is the worst defender I've seen at United, but I can't give an opinion on worse prior to him.