Do any of the Lich-exclusive companions have dialogue with other characters?

Specifically, I'm curious if >!Staunton!< reacts to other characters or events once he's in your party. He's kind of terrible in terms of build, so I don't drag him along with me, but I want to know if he has any exclusive conversations with Minagho later.

Some of the other Grave Guards seem to be incredibly strong, but I'd rather not bring them along if it will kill the party chatter.