Hey, @den, thanks for offering more info about this! 
Just out of curiosity, did any of those playthroughs include a purge?
These days I play solo on official servers, which means that I have to be prepared to face a purge without any other players, just in case. My typical strategy for those occasions is to place one or more thralls around my base, each covering a direction from which enemies might come. That way, in each wave I can deal with one group myself while the others are engaged in fighting my thralls, and when I’m done with that group I move onto the next one, until I’ve defeated the whole wave.
What worries me about this nerf is that the group engaging a thrall without my help might manage to kill that thrall before I can come to its rescue.
Is there anything you can share about how the post-nerf thralls perform in a purge?