Well then they should have made less death arenas and had more enemies come streaming in, as it is now the options are shoot out with 20 dudes who kill you super quick or stealth with minimal options.
I stealthed most of the battles just because it was easier to do than try to fight off 20 dudes who were all bulletproof
I don't know how you were dying super quick on moderate difficulty. Having a shoot out is what's fun as you don't have to hide behind cover to shoot.
Check out this clip of what I did in one shootout for example
i purposefully killed the two snipers and then engaged everyone. That made it easier to fight the enemies on the ground. Plus if you look around there were other power weapons scattered about like a the Balrok or w/e it's called. Also there's explosive barrels and that door has a bomb on it that you can detonate.
I did this level like 5 times to see how you can tackle it and there's a lot of ways to go through this area. The options are in how you go about fighting and what weapons you use, where you go, buddy kills etc. It's really fun.