age difference

The age thing doesn't bother me much because Mulder is older even if it's only by a couple of years, and it could be more. But he is not taller. Mulder, Krycek and Skinner appear to be around the same height. There's certainly not enough of a difference to be mentionable and yet Mulder is usually described as noticeably taller than Krycek, and Skinner as if he towered over both of them.
I don't know how reliable it is but IMDb lists their heights as NL 6'1", DD 6' and MP 6'2".
(NL's birth name is now down as Nicholas Herbert. What's that about? It used to be down as Nicholas Shroeder.)