Indeed, the Soviets units being the only cavalry to mix cavalry with battle tanks by design and so late in the war as well (also the only nation to form Corps level Cavalry formations). I always wondered about the sense of this, but I suppose what when you lack motorised infantry in and are on the offensive, but have lots of cavalry, the cavalry will do. It might be interesting to look in detail at the actions these Russian Cavalry Corps fought in. This also occurred during the last days of the war on the German side with SS cavalry units being gathered into combat units (Brigade/Division) with whatever else was available, but not as a considered tactical concept.