I think you've misunderstood me, Sterling doesn't like to get in a foot race, he slows things down to allow himself to use that explosive couple of yards to get himself away from a defender, basically starting from a dead start, he's what I would call a nippy winger, but not a real speed merchant in the way of walker, for example
If you lined him up in a 50 yard dash with Walker, he would be in front up to 5/10 yards, then Walker who has genuine sprinters pace takes him
His cutting back is due to the inverted wingers he needs to come back inside on his favoured right foot
The Villa game where he crossed from the right for Gundys goal was what Raz wants a couple of yards a cross a goal
He isn't really the type of player for an inverted winger role, there are better options in the squad, Grealish, Foden, Bernado etc