Regarding: Covenant not being able to counter a unsc vehicle depot.
The basic problem isn't hunters. They counter all covenant vehicles and UNSC vehicles, except for scorpion/Grizzly well. The problem is that canister shell does too much damage at 2,000 to 3,900 a shot from each tank so that they can wipe out hunters before they have a chance to do sufficient damage. Combine that with the explosive 1.4 multiplier against heavy infantry and the damage is upped to 2,800 to 5,460 against hunters that have a maximum HP of 4695 at assault beam so they are one-shot killed by grizzlies and almost killed by scorpions.
The solution is to change the OP of canister shell. Either,
a) nerf canister shell damage
b) change the multiplier of explosive damage against heavy infantry from 1.4 to a lower number so hunters stand a chance against tank spam.