I think a thunder gun grid is pretty good overall in the long run. My dream thunder grid is 2 Mammon guns, Phantom gun, 3 Olympian guns, 2 Marduk hammer, and 1 Raiko hammer with the meta thunder himes. With vigoras in it's own bracket, you can pretty consistently hit cap amounts of damage using a 5 vigoras weapons grid. In my calculations, it's actually very very difficult to hit the 350k cap with just assault and elemental multipliers alone. You could, in theory, do it with double MLB nid, thunder aphro's vigoras buff, kaiser buff, a whole bunch of raiko hammers, and a glass cannon hammer grid. But it's mathematically a lot easier if you make your vigoras multiplier bigger since you're getting significant diminishing returns from assault in that hammer grid.