This usually happens when you have mission-hazards from tarrot-cards or other sources active. Main offender here is "+1 additional champion spawn in champion groups", especially when you got 2 or 3 of em. Champions with fixed spawn locations (like turrent or sporecysts) then spawn on top of eachother. It can be alittle annoying, but hey... they can drop loot and supply-boxes(when you got the innoculator enchant for it). So it can be very rewarding. The annoying part is that you usually can only kill them one after another and not all at once.

Ah Thank you, I had been wondering about this same issue as well... Now I know but yeah is a bit annoying that it doesn't spawn at the same time. :-)

Hi, simple solution would be to remove champion tag from turrets and stationary enemies like sporocyst so +1 champ card will only affect roaming units