The Alchemer, Alchemer Mk II, and 4* Driver models have very clear distinctions in their silhouettes and color highlights.
The 5* Driver, however, is simply an extended 4* Driver. I would very much like it if the 5* Driver had as dramatic a visual change as other 5* handgun models. The Autogun line has an improved visual progression after its update, and I wait to see the same done for Alchemers.
I was just like 'whaaaa?' when I looked at the alchemer series. It's just extra alchemy tanks on the sides! I even preferred the 1 or 2* versions!
Perhaps give them 3 slightly larger tanks, and stack them pyramid style lying horizontally, with all of them attached to the output nozzle?
I don't have any other idea, but seriously, they just looked like they clipped on an extra few tanks!