So I cleared out Black Mountain, and there is this ghoul, Raul, who I assume we can recruit. First he denies my request to join, saying that I already have a full party. At the same time message pops up saying "you can only have 2 companions at a time". Fair enough, I had Boone and ED-E (whose quest bugged for me and I was stuck with that flying thing and wasn't particularly amused with its abilities). Needless to say I dropped her instantly and talked to Raul again. He refused yet again, saying same thing. Message pops up again saying "you can only have 1 companion(s) at a time". ONE! ONE? WTF? :brokencomputer:

The messages are worded a bit poorly. You're limited to one "humanoid" companion and one non-humanoid. So while your max is technically two companions, you can't have two humans/ghouls/super mutants/etc, or both ED-E and Rex.