I think that having complementary skill sets is important, but I'd say that after technical skills, interaction design skills are probably more important than business skills. Like they say: first get to product market fit, then grow the business. Getting to product market fit requires someone who understands user needs and interactions (product design) and someone who can implement the solution (technical). A product/interaction designer, though, will probably have some frontend development skills, so perhaps I'm arguing for two technical people.