Oh, yeah I love that. Those subtle changes in ships and guns, kinda give the illusion of being improved. Kinda like the changing aesthetic in Star Trek adds to the illusion of technology changing.
Though for Star Wars, Rogue One kinda messes up the AT-ST. As they use the ROTJ version...... But then again I feel the ESB version was probably only meant for a single person. I like to think of as a sort of Special Forces AT-ST.
Have you seen this video on this subject?
I would almost give them a pass for the AT-ST in Rogue One because equipment could be in testing for years until they are fully deployed. I could totally see the Empire, like the US military for example, field testing advanced designs in small numbers. Not to mention that Scariff is directly involved removing crystals from Jedha, and Scariff is involved with design, so it's entirely possible they do some testing there. So I wouldn't be surprised if they had the next model AT-ST available there to deploy.