If i recall correctly, Stormlord is the one with the vulcan mega blasters, right? if so, it chews right through infantry units and the lascannons for anything bigger! Really good tank, used it once and it lasted the whole game killing nearlly 3 squads of Orks and a killakan! If you don't move you can use it's beast of a gun TWICE!!!
EDIT: missed iportant info...put some heavy wepons teams with lascannons for extra killy on top or just 20 gaurdsmen with lasguns (still killy!) And just look at how many heavy bolters there are!