Interesting...but, yes they did want the 152mm main gun. They've been in love with the 152 ever since the SU-152 was knocking out German heavy tanks with HE ammo in WWII. Soviet tanks like the Object 477 and Object 195 were intended to fight WWIII with a 152mm main gun. The corruption/political factor is huge and probably more controlling than most folks realize...that said, why dedicate all the resources and effort required to turn away from traditional conventional turret designs, and go with low-profile or unmanned turrets and elevated main guns? Certainly not for the 125...an unmanned or almost unmanned turret was needed to make room for the 152mm gun and autoloader. You're right about the Object 195; its development was pretty far along with a 152mm main gun. The development of the Object 477 was also moving right along, again with its 152mm main gun. The Armata platform lends itself to the addition of a 152; the crew has been moved to the hull and the additional length gives new needed space for a larger autoloader. Maybe the plan was to field both a 125mm and a 152mm version of the Armata? The more powerful version could be organized into assault gun or tank destroyer companies...and we know they've done that before.