Talk with a few advisors and lawyers individually, and then if you still don't have a clear idea, maybe meet with some advisors/lawyers with both of you in the

Talk with a few advisors and lawyers individually, and then if you still don't have a clear idea, maybe meet with some advisors/lawyers with both of you in the room. If all else fails, I'd re-write the business plan in terms of who does what. What are you good at? What aren't you good at? If he has a bad sense of design, maybe he shouldn't be handling that aspect, etcetera. With that said, I hope that all goes well and that this startup succeeds!