Ok, big generalisation:
It seems to me that height often corresponds with a certain body type. Many tall guys are lanky ectomorphes and find it really hard to add mass to their structure. On the other hand, you are generally more likely to find that 5’8” guys are mesomorph or endomorph and add bulk more readily.
Another issue is calorie intake. As I said before, at 6’4” and 250lbs, I don’t think I look massive. However, to maintain that weight I need to eat a lot! Not sure of the calories, but I’m eating quality high protein meals every 2/3 hours. My training partner who is 5’9” and 200lbs (ish) looks massive to me, but can get away with an average diet with a few protein shakes chucked in.
PS I don’t get this Lee Preist AS poster boy thing, pick almost any of the bigger top pro’s and they are the same. They need to be to compete against each other. Also, most of them will consult the same “experts” on what to do anyway.
Also, I have met most of the top Mr O pro’s, and I am always surprised by how short they are.