<Snipped quote by Framing A Moose>
I think I was rememberin one of Bright's suggestion for why Phoenix would join. I still don't think just his daughter could keep him from destroy other. If it was there would be no need for someone to approach Firebird about the program. Nor is there a reason for him to agree to putting her into an arrange marriage.
You'd be surprised. She's the only person he loves, so he'd probably do a lot for her. And a reason he'd accept is that it gives his daughter a chance to get out and take a bit of a look at the world. Besides, I don't see you questioning why Pheonix is there and not why Roman is there.