People are rather poor at guessing the height of individuals. Photos don't always show the differences, either.
Here is Jay standing next to me some years ago. I am 5-9 1/2". Jay looks to be about the same height as me.
I measured Arnold's height at 6' 1.5" in February 1969 at Mits Gym in Honolulu. All this rubbish about his height being much less is nonsense.