Recently I had to face a runaway civ who had sole possession of it's continent. It was somewhat more advanced and had twice the units and more cities (75 against 60) but there was a tactic even in this case: 1) I fought with smaller opponents to generate MGLs. 2) Created and landed 9 cav armies. 3) The armies were split in two stacks which razed cities. 4) Once only the core remained the stacks were combined and artillery were landed and rushed to the front using former enemy rails. 5) Core cities razed and conquest VC achieved. Two armies created after the initial landfall hunted down all resettlement attempts. The war lasted about 100 turns, 400+ enemy units defeated, 1 cav army lost and thus 35 units dismantled a huge AI empire at puny cost. Is this a good tactic?