It needs some extra consideration. More can always be said on the matter, especially about the early war performance of the Red Army, so if anyone wants to have a go at it, please go right ahead! However, for the late war casualty ratios, there's a lot more than just 'callousness' at play. Such is covered in this previous thread, with contributions from u/K_K_Rokossovsky and u/Jon_Beveryman, among others.