Well standard Stormtroopers tend to be more widespread and used simply as patrol, but also for simple attacks when necessary. It makes sense that we only see standard Stormtroopers in ANH, as they were simply searching/patrolling the streets of Mos Eisley, and the Death Star is such a stronghold that the Empire wouldn’t necessarily need to keep any specialized troops on it, especially as it was only just completed right as the movie begins.
In ESB we see Snowtroopers which is great, but once were off Hoth we only see standard Stormtroopers again. To me, it works. Vader and a few Star Destroyers are looking for Han and Leia, and they have the whole thing planned out with Lando. There really isn’t a need to have any specialty troops running around.
Now in RotJ, this time we have a Death Star secretly being built on a planet which has no civilized (or perhaps I should say advanced) populace or major threats-- at least in the eyes of the Empire. Keeping specialty troops around doesn’t seem entirely necessary. But it certainly does seem odd that the Scout Troopers were not camouflaged. One could say that without any major threats on the planet, the camouflage is unnecessary, so they might as well stay white just to increase their own visibility in the woods. But nevertheless, it still seems odd.
This time around in RO, the Empire is hunting a dangerous espionage team, across multiple Imperial occupied planets. It makes sense that they pull multiple types of troopers from their local bases.
That’s a good enough explanation for me, but I know others aren’t always satisfied with that reasoning. Cheers either way!
I would actually love to see Disney completely rehaul the OT adding new ships and troopers, cleaning up effects, and what not (sort of like a special edition done properly). But let me say, I ONLY want that to happen if they ALSO give us the original unaltered versions in HD on the same release.