Just from a quick check in the editor, I put 5 missiles in to the T-72 and it's showing 0.6 damage in the console, getting in to the vehicle shows all systems as undamaged.
Also fired a few missiles at a T-34 and it didn't seem to take any serious damage. Titan killed the T-34 in two hits (still seems excessive!).
I'd expect this old Russian armour to be killed in one hit. There is this footage on youtube of them training with the Jav and it seems pretty effective. https://www.youtube.com/watch?v=Wffv5NCrrvc