I would think that every soldier ever born, except maybe the great Audie Murphy, would be “casualty averse”.
Audie Murphy earned his medals by putting himself in danger and taking chances with his own life. He did NOT sacrifice the lives of his buddies and later soldiers under his command. My interpretation of “casualty adverse” is that the average Russian “Private Ivan” lacks morale and has no trust in his officers as to why they are fighting this war.