Also on a hgv trailer the axles are at the rear so there is very little if any weight behind the pivot point of the axles, whereas on a standard trailer the axles are central so there is a far greater distance of bed away from the axles so it is more sensitive to being oddly loaded
depending on number of axles and the spread of the axles(distance from center to center) you can over load a hgv trailer and have no steering or bad tail wag