I have to agree with this. But I was quite surprised at the difference in power between them. I had over 50% health after killing the first one, and over 90% when killing the second one. Hell, I didn't even use electrocute on them. While on the 3rd one, well, I died when he had around 10% health left, and I used electrocute on him. Last one.. I used heroic moment so I don't know how it would've gone without. But I had 50% health when killing him.