With all of those? Or are you saying any one of those kills you? Because they aren't that terrible. The bombs they lob are kind of annoying and hit hard, but eh....
The actual hard elites in Act 4 are the Morlu Incinerators. With even slightly bad mods those things can ruin an entire run quickly. They all have teleport, which means you can get all of maybe 2 hits in before they teleport and slam another meteor on your head. Annoying if it's just them on the screen, but devastating if a Mallet Lord or something also happens to be around. Those things are just crazy...
They have multiple abilities like my screenshot above. People just quit because they get raped. It's not like you can kite whatsoever against them with a melee.