I tried doing a run as Siugnas with as many summoned followers as possible, but it capped at 4 followers even though i had a lot of Max. Health (dont remember exactly how much i had), so i thought its just the genuine cap. Now after doing a Run with Astarte it again capped at 4 followers, but the Wiki states it should cap at 10 with Lvl.95+. As seen in the Screenshot i was Lvl.132 and no more then 4 followers spawned, so i would assume its a bug for both Characters not turning more then 4 enemies into followers.
Update: Did a run with Lolo, Hiss, Meow and Purr and could get unlimited followers, so it has to be an issue with the "turn enemies into followers" mechanic
Platform: PC, Epic Games Store
Game Version: 1.14.111