Argh! There’s a bug in the mission generation code that will create missions up to 40% harder than it should. This pushes the difficulty outside the normal bounds, and the RNG is doing its best to make things more difficult by spamming mini-bosses.
The missions on the screenshots are pure deathtraps – it’s a wonder people are still trying to politely suggest that perhaps difficulty is a tad too much and don’t instead pick up their pitchforks and try to kill me in my sleep. 
And I find it even more amazing that there are players out there that take this in their stride, like it’s no big thing, eh, we’ll manage. You guys are heroes!
Anyway, in the next update the difficulty will indeed be scaled back to fit inside its expected operating range. HOWEVER you difficulty freaks should not despair, because skills are being reworked and will probably change from controlling enemy health to boosting mission difficulty. So it will still be possible to boost difficulties past their limits and get these types of insane missions (you’ll just need to void your warranty by explicitly choosing it).
More details here: