OP already has the 6.8, and bullet selection is getting better to where it can get closer to Grendel ballistics than before.
I'm a huge fan of the Grendel though- and now that Hornady has introduced the 123 V-Max in addition to the AMax, it should make an awesome hunting round as well.
But I'm not sure what the OP is looking for...
The .223 fits the varmint/dog bill.
The 6.8, deer and hog- though "bigger" would be better for big boars.
The .30 cal selections are only "good" to about 100 yards- then they drop like a rock and lose substantial energy. If your shooting is inside that range, worth considering.