First of all Stalin wasn't Russian. Second what were the low casualty options exactly that he could have taken but didn't (because obviously he had total control of all levels of military strategy)? The USSR alternatively ceded ground with scorched Earth to save lives, dug in to fortify when the strategic situation demanded it or when they could effectively use terrain as a force multiplier, used advanced weapons and combined arms warfare just as much as anyone else did, and attacked in force when the gains could justify it.