To be fair the rocknose purge was pretty tough as well.
But there is a thing all purges have in common:
They are only a threat when they actually spawn in! 
Yeah. A Grey One miniboss caught me by surprise yesterday, and those guys still hit like truckloads of bricks.
Well, he got the one hit in. It was not enough to kill me. And luckily, the machine-gun harpies don’t turn in the middle of the feather spray attack - that would’ve been brutal.