Something strange is going on with followers while exploring. Very often when there are multiple enemies and group members proceed to take care of the first one, once they kill it they seem to freeze for a second or two before attacking another one. I've noticed it nearly straight away after downloading that newer Version 22 build and starting a new world. IIRC in the previous build the followers were taking on the enemies one after another without any delays. Here's a bunch of stitched together clips showing this occurring: