The drop rate is pretty garbage honestly, doing the quest to get another nine is a giant pain unless you can just buy them at the fort.True, but to be honest, I never (okay, most of the time) recruited Cait anyway.
I also literally found out this weekend that you could recruit Viviane, because I've never dropped succubus milk (or I just don't remember dropping it) to get the quest, like or I'm just unlucky as shit or the drop rate is garbage. I'm not joking, I genuinely never knew about it (unless her being a companion is something new).