>>Russian tanks are vulnerable to Western anti-tank weapons like the Javelin and others
I'm pretty sure all tanks have similar top-armor vulnerability. I think Chobham style (multiple layers with an air gap) armor might work - but so long as there are turret-top hatches the armor there is going to have weak spots. The upcoming tanks with unoccupied turrets (e.g. Armata, AbramsX) might address that. Yes, the RF nominally has the Armata now, but they only have a few, and those don't seem reliable (one in a Moscow parade had to be towed due to engine/transmission issues).