Startups are not a place for an MBA to get engineers for free but a place for engineers to make bank if their egghead managers in their corporations don't get going with an interesting business idea of which they know that it is a missed opportunity.
If you are failing to attract these high-end engineers to a low paying job, perhaps it is because they dont see what unique skills the "business person" is bringing to the table to balance the risk.
As an extreme example, I'd guarantee if the "business person" was Elon Musk, people would flock this startup. What high-end Engineers do not want is to give away a lions share of equity in exchange for a pay cut with no real upside, that would make no sense.
The typical procedural founder with "business skills" may have solid business skills, but those can be hired anyway, the business founder needs to demonstrate equal 500k-1M level of skills/background/trackrecord/etc.