If WH40K tanks looked this good, maybe I would not have sold my collection.
Yes, there is the part in the old fluff (1st edition/Rogue Trader era) that explains that Imperial vehicles look like tractors and prime movers because most of them
are originally militarised versions thereof, only the knowledge of such machines having been preserved through the Long Night aka the Age of Strife. But to be honest, even for militarised Caterpillars, they still look too toy-like to my tastes (for example, the Russ having no room for the gun's breech inside the turret never mind the commander, gunner, and loader...) Of course, the RT era fluff has been retconned since forever and the Russ is now presented as a proper main battle tank. Therefore, and my reasoning is that the WH40K models are actually meant to represent
in-universe toys of the respective vehiclesmeant for Imperial children, explaining the humongously exaggerated comic-book like features.
Long story short, your creations look very much like what my headcanon imagines the
real Russes to look like in-universe if they indeed were proper battle tonks
However, how are you going to solve the problem of adding the ubiquitous gun sponsons? By designing a separate hull with fixed sponsons, or coming up with a solution to have "modular" sponsons that could be installed as necessary instead of side armour? Or by retconning such WW1 relics away from the universe altogether?
(That said, the entire concept of Russ is obviously by a person who understands nothing of tank warfare - in most Russ variants your most potent anti-tank weapons aka lascannon and multi-melta are illogically not placed in the turret which would have room for one, but in the hull or in the sponsons, Vanquisher and Annihilator being rare exceptions.)
