GC is very powerfull. The 2nd most powerfull land unit in the game. There is also I dont think a cost effective way to kill it with land units because of its claws however every other land experemental in the game can be cost effectivley killed by T3 land. If it did not have its claws percivals would own it hard but as it does it owns them hard. They can grab any non commander and non experemental land unit and insta kill it.
few sugestions.
-making its claws not able to pick up bricks or percivals
-giving its claws shorter range so it will still cost effectivley kill T3 land units if they get close but not so much if they stay out of range of them (my favorite)
-making its claws have longer reload time. At the moment its as soon as it kills one unit it picks up another.
-making heavier units take longer to pick up