Every attempt to land on a tank has resulted in the tank not dying in my experience. This is however a double edged sword, as it means you can plant a hellbomb on top of them.

Tanks are one of the few enemies NOT damaged by hellpods. They are effectively mobile terrain, you can mount sentries and supply drops to them. If you cover the red ‘eye’ on the mantlet (plate the cannon sticks out of) you actually blind them and they basically can not attack you save driving over you when they hear footsteps.

Fabricators and mushrooms are my personal favorite targets