>>95869106
>are cadians and catachasns canonically taller than other regiments/average dudes in the imperium?
Catachans are based off Rambo and the marines in Predator. Going by the main actors heights which are 177cm to 190, yeah.

I wouldn't say all Cadians are also gigachads, but Cadia set the standard for the Imperial Guard. In the same Eisenhorn novel the Cadian Inquisitor was a stocky woman but not very tall.
Karskin are the elite of the elite. From training and whatever special food and steroids they are fed, to possible augmentations, they are gigachads. They should be tall and very strong to carry all that armor, gear and the hellgun capacitors all the time

I remember reading somewhere that the average human height in 40k is close to 2m. Might be one of the many reddit lies.
Ciaphas Cain is "just over" 2m tall, or 6'5". He's taller than the average nad usually the tallest in a room, which is why he often sees danger coming first in a crowd.
Eisenhorn is self described as tall but i don't remember real numbers.

If the average height among the Imperium is 190 to 200cm, then the gigachads are well above 2 metre tall.