I understand why Antony isn't working out (can't really spot a pass forward, good but not amazing at creating the space to shoot with his left, no right foot (contributes to why he has trouble getting a shot off on his left), not strong enough to get on things at the back post, just lacks the one great quality that makes a winger explosive).
Why Sancho isn't a City-style winger slowing things down, retaining the ball under pressure and helping pin teams back when we have the ball and being useful on the counter as a smart passer and fairly decent (say 10 league goals a year) goal-scorer, I have no idea whatsoever.