Pershing isn't a pinnacle of durability, in fact its durability is very average.
Panthers have no problems against it, PaKs do the job as well.
If you managed to get 3 comets, then you have won the game probably before you could get first one. It costs almost 200 fuel, hefty amount of menpower, takes a lot of population which will already be occupied by pop hogging brit infantry, it can not be spammed.
Cost decrease might lead to its spam, therefore that solution should be last, its AI performance needs a buff, because its AT one is fine where it is at.
