I really wished now that I tested the old centaur with hull down to see if it could take on AT guns armies.
This ability is more map situational than anything, the few times I setup hulled tanks is when they are in ambushing spots such as the bottom right cutoff of Angoville so long range units have difficulty against it. Maybe more tank camo is what hull down needs
Plus the reduced damage take is great against indirect fire like if a priest just starts firing on them out of nowhere and they happen to be hulled down you might take a few hits then unhull and run out.