The Devitt Ironhide Mk. IV has 1950 HP and is disabled under 20% health. It has "Heavy Armor" resistance: it can soak small arms fire, shrapnel, and 12.7mm machine guns, and it is immune to Flamethrowers. But heavy explosives and anti-tank weaponry are a real threat to it. It has subsystems that have a chance to be disabled by heavy explosives and anti-tank weaponry if hit specifically: Tracks: 25% (Anti-Tank Mines always disable them), Fuel Tank: 20%, Turret/Cannon: 20%. It has Tank Armor. With it, in best case scenario, penetrating projectiles only have a 30% chance of penetrating and doing damage. That chance goes up quickly if the armor is worn or if it is shot from up close, or on the side or rear from a direct angle, or with ammo that has penetration bonuses. It takes 135 Basic Materials to fully repair it from 1% to 100% health with a Hammer. Its health, subsystems, and Tank Armor can be instantly repaired at a Garage for 100 Basic Materials.
They are vulnerable to Anti-Tank Mines. Although a single mine won't kill them, it will cause big damage and always disable their tracks leaving them vulnerable to enemy Infantry with Anti-Tank weapons.
Enemy infantry with Anti-Tank Sticky Bombs also represent a danger because they have a good chance to disable the tracks as well.
Although it is possible to use a Light Tank without a Commander, it's not recommended as it will limit your awareness on the battlefield.