He got one albeit a very good young one and tried to get another (Upamecano). They are rumoured to be going back for him in the summer when his release clause drops.
Man Utd got a 'quality ' CB and still concede goals.
Sanchez at Spurs cist £42m and doesn'tlook anything special.
I do keep half an eye on Arsenal, due to growing up with the great Wenger teams, and I really thought in the summer that they could have a go this season if they sorted out the centre of defence. I know that Holding is rated, and I liked what little I saw of Mavropanos when he had a spell in the team, but it still lacks a true leader in the mould of Adams/Campbell. Fair enough if Emery is willing to wait for Upamecano, like Liverpool did with van Dijk.
I'd say that the rest of the squad is mostly very decent, aside from Xhaka, who I honestly believe to be the worst midfielder in the league bar Schneiderlin.