If your "ideas man" has fully committed to doing all the sales/marketing and the dance of raising capital, leaving you to work on the product, I think that's a very fair division of labour. After all, a finished product is almost as worthless as an unexecuted idea if no one ever actually purchases or uses said product. I say almost because, in theory, your product could have enough "obvious" value on its own that you could just sell it to another company and exit comfortably.

But now they are taking all the risk and it would make sense to just pay you a salary and keep the 100%