Guest Party Members? (Patreon)

Something I've toyed around with the idea of a bit is having segments in Project Red where you'd have a secondary party member.  For example, during Red's raid on the thieves den, she could have the hunter Hati in her party during that segment.  There's only really two characters who would realistically join with Red in battle, that being Hati and the Witch.  So I've been hesitant to spend too much brain power on it, especially since the balancing of the game would shift greatly with you having 2 characters to attack with.  But I figured I'd poll you guys for your opinions.  What do you think, would it be cool to have some secondary characters to play around with, even in a limited capacity?