I came across two Hadrians a while ago in this play through. I could interact with both of them during the Three to Tango Quest. they both showed up at the 4 Aces, too.
One Benny is too much. Last night by The Prospector's Den, there was a man and woman whose torsos were combined. One was walking forward and the other was trying to walk the opposite way so it was a two-headed, four-legged person for a bit. I walked past and they separated but it was trippy.