and this guy too, cause i figured if you aint an officer you're just some enlisted/conscripted like everyone else and i don't think vet sgts of diff units get special treament from those of other units.
Well, I guess they are all just grunts- but some will have earned the respect to be allowed to use a power weapon (or even a power fist for a veteran squad sergeant).
Rough riders are more likely to be seen as heroic, dashing off and assaulting the enemy, acting independantly behind enemy lines, it goes with the background that they would be given powerswords. Their sergeants are closer to being officers anyway - some probably are. Aristocrats and their horses.
Storm troopers are the best of the best that the imperial armies can muster (aside from space marines, but they aren't
really imperial anyway, so thats different).
They are given the best training, and access to the best equipment such as targetters, hellguns, carapace armour. It follows suit that their sergeants will be seen as somewhat higher in rank than their equivalent amongst the regular grunts, something which probably adds to their derided reputation as glory boys. Thus, they would have more access to power weapons.
As for veteran squads, well, these are soldiers that have survived for very long periods of protracted warfare, probably several campaigns. They know how to act in varying situations, and thus would more freely be given the equipment neccessary to fully carry this to effect. More than this, they would have collected trophies and other wargear throughout their battles/warzones, and the higher-ups might turn a blind eye to the occasional powersword or fist slipping through, knowing that these guys work better without being told what to do all the time.
(Until some new general [read: me] decides to give 3 of them plasmaguns and deepstrike them right into enemy lines. Whup - there goes over 100 years of collective battle experiance in one hit, but at least they took out that leman russ {confused} )
Everyone else, is simply expected to die for the emporer, but not before running out of ammo, or breaking their bayonet. No powersword for you. A veteran sergeant is expected to run out of ammo, pick up some dead green grunt's unused gun, and then run out of ammo on that too, before dying).
Just my thoughts, mind you. Dont consider them gospel either, I hear thats a path to insanity.