That's a biggie for me, too. One of the things I'm working on is my Hall of Heads. I am not doing full costumes for several of these, but just the helmets, so I have a full lineage of: Old Republic Trooper => Phase I Clone Trooper => Phase II Clone Trooper => Phase III Storm Trooper (from the Kashyyyk scenes in The Force Unleashed -- transitional between the ROTS look and the OT look) => Phase IVa Storm Trooper (Solo version, still in use at low-priority Imperial installations years later) => Phase IVb Storm Trooper (gestalt idealized ANH/ESB Stunt/Hero) => Phase IVc Storm Trooper (idealized ROTJ) => Phase V Storm Trooper (Legacy version).
Still debating the First and Final Order Troopers, as that's a parallel track, part of Palpatine's Contingency, and more straight Sith than Imperial. Thus, arguably a different narrative.
I'm also doing a SpecOps lineage: Phase I ARC => Phase II ARC => Imperial Commando => Storm Commando.
The stuff I have displayed I want to tell a specific visual story. Same as I could see some variations between E-11's being different manufacturing facilities, while others would make more sense as different points in production lineage. I point to the Mauser C96 as an example. All the variations, early to late, different chambering, different trimming depending on where a particular one was made, or for whom... But all still recognizably the same gun. The Emperor had "an entire Legion of [his] best troops" waiting on Endor, so I consider that version of the armor and blaster to be the latest and best. That factors into how I approach the props. If I were to display an ANH E-11 -- with the cords and all -- next to an ROTJ E-11, the former would have a bit more wear to the bluing on the edges that snag, subtle dings from use in the folding stock and magazine housing, etc. The latter would be more pristine and shiny and all the markings clear and readable.
That, also, for me. I do a "wardrobe" approach. My TNG era Starfleet persona has a closet full of the appropriate attire: Dress uniform, class A duty uniform, class B duty uniform, class C utility uniform. My Royal Guard persona has the formal robes, the TFU armor under that, flight gear, Stormtrooper armor, Stormtrooper officer's uniform. Both have the appropriate weapons and accessories, and nothing more. The latter, for instance, has the force pike, the holdout blaster, the SE-14R blaster, and the Merr-Sonn blaster, but no E-11, as it's not one they've been shown to carry/use, though I have no doubt they are well trained and capable in its use.
It's a fun mental exercise to figure out what to include and how to portray it.