He is far from narrow, and merely needs a little more upper body width to compensate for his (slightly) long torso plus some more hamstring thickness. If he continues to improve at the rate he has over the last couple of years then he has no worries. Zack needs to dominate the British Nats like Dorian did and he will have no problem going pro and getting the necessary endorsements etc. No need for him to move to the US.