Why do you need the business types to be co-founders? Why do they get shares at all? Why not hire them as employees (or temporary contractors)? Is your proto

Why do you need the business types to be co-founders? Why do they get shares at all? Why not hire them as employees (or temporary contractors)? Is your prototype done? If not, why do you need business-types now? What value do they add? You should retain majority if not 100% of the shares. That way you have more shares left in the pool with which to recruit engineers.