Personally I enjoy warmongering and like to go to war early. Especially on higher settings. I feel like the money from enemy cities, the additional cities and expansion, and the techs they are forced to hand over makes it a very viable strategy to keep up with the teching and over expansive capabilities of the AI on higher settings. Plus its the most fun.
That being said it, this works best on epic when u have the most time to finish a conquest and get their techs. In BTS they have made it a lot harder to get Great generals. I always thought GG were essential to fighting continuous wars cause ur losses are a LOT less with wardlords. And hence less war weariness. SO i use imp trait.
I Like going Cyrus (imp/char) to get my GG and to make them warlords with -25% xp amplifying their power. Romans are an excellent combo. I usually hope for that quest to build 12 swords and i never promote my praetorians cause if i get it then i can have 12 with city raider I/II. I also try to start near iron and stone for pyramids (and hopefully stonehenge, which is possible to get both in epic) cause then i can go straight to construction and not worry about gov etc.
Then its just war for whole game. I had 6 Great general warlords by renaissance (3 of which were level 14, and one on my catapult was level 12). Not easy to stop this army no matter what your defenses are.