My thoughts:
First off i managed to roll the full 12 shields for both gargants in the beginning of the game. My opponent sobbed quietly.
a great gargant with 13DC and 12 shields can take a beating!! Like KIC pointed out to me in the gargant thread this kind of build and tactics could prove to be very, very hard to beat. But every game would end up going to points after 4 turns which is not very fun.
You can effectivly deny both the Blitz and BTS objective by sticking a defense orientated great gargant on the blitz. You let the Huge Stompa Mob guard 1 of thr T&H objectives to deny T&H.
Objective placement like i did here makes it easy for a GG to contest both T&H objectives and thus denyng the DtF objective also...
So my thoughts are that it might be a good idea to put a 0-1 restriction on Mega Gargants and Great gargants in the list (cue loud protests from Kadeton

) in order to avoid that the list becomes a 1 trick pony thats very boring to play and face...