Yeah I sorta followed the same tactic. I killed the Chimera first, but then I went for the Gorechimera and while I was killing it my pawns were killing the Lich. At least I assume that's what happened because it fell dead right near me just as I was landing the killing blows on the Gorechimera. They worked amazingly well together. The two Chimeras and the Hellhounds are all really good at knocking you down, and knocking down off of the Chimeras, between the Hellhound's fireballs and the Chimera's roars, and the Lich would just fly around and cast spells on top of you while you were trying to deal with them, and continue summoning endless Hellhounds. Everything about it was rough.
Now that I'm towards the end of the game, I have to say that I'm not a fan of the random chest loot thing. I could see doing it with some chests, or even most chests, but it's pretty rough that they don't reward you with good equipment as set chest items at all. It pretty much means that you could run through the entire Everfall and not get a single equip if luck was against you. So far I've only gotten maybe 5 things, out of like 20 chests, and the majority of them have been heavy helms, so it's not like I'll be using all of them either, and it's just irritating feeling like I have to cheat the game in order to get good things in the final dungeon. It's dumb. Don't get me wrong. I've enjoyed the game as a whole, but now that I'm at the end, and I've experienced the brunt of some of their extremely poorly implemented systems, I have to say that Capcom should stick to what they're good at, like fighting games and action games, and leave RPG's to the professionals.