If you only care about the OT, then why do you quote wookipedia? Where in the movies is it said that stormtroopers are the elite soldiers. This would mean there are also “normal” soldiers, which are not stormtroopers.
Well for me it is not only about the OT but also the EU. I thought that my avatar makes this clear enough.
And even there is a continuity in stormtrooper-design and -purpose. Even in the PT you can see a continuity. Even in TFA the design makes sense and looks like a “natural” design development:
The RO-stormtrooper-designs does not fit.
And when i relate this to the real world and to real military designs, the form always follows the funktion. An armor that “represented some of the best in the Empire” would never be optically redesigned that much. You do not need to redesign a scout trooper to a shore trooper.
Thats all only for merchandise purposes.
And after all it does not look like a design in the Star Wars universe.