I've always noticed the 5th Snipers are way more dangerous with their pistols, they do a TON of damage per shot. They do much more damage than wardog/hades. I suppose it's their balance, as they get dropped in 1 punch. Hades have a lot of health so it makes sense for their sidearm to be less deadly. Wardogs have constant regen but still low max health.
For brutes, Wardog and hades can fuck you up in a second. They just take a few seconds to start using their shotguns after getting wounded. If you shoot them down from far enough and approach, they will blow you away. But yeah the 5th brutes are annoying and almost impossible to advance upon, due to the massive knock back they bring. It's like trying to fight a tolchok when they get wounded! I've even seen them shoot me point blank in the middle of CQC, they have rolled away from a punch and just immediately shoot me as I was trying to follow up.