This year the signings were horrendous. Kehrer in particular is terrible, Paqueta has been average and they didn't really want Scammaca, they wanted Broja who should've left given that he's now about 10th choice at Chelsea.
But he was made good signings at West Ham that made them good last season - Coufal, Soucek, Bowen etc.
He was very good at signings at Everton. Piss poor at Sunderland. At United didn't really get a chance. Overall I'd say he's better than most but fallable as the manager-centric approach often is in the modern game.
His biggest weakness seems to be when he signs played from the big clubs or players that have some hype about them - e.g. Kehrer, Scammaca and Djoboudi from Chelsea. It's the lesser known players that must have been scouted well like Coufal and Soucek that he tends to do better on.