Founder skill sets should complement each other, but that doesn't mean one needs to be an MBA. Unless it's a case where it's founder who has pondering the problem for years, is the source of the insight ,and they just happen to have an MBA too, investors tend to view MBA founders as a net negative [0] vs strong technical team.
Ideally you want a brilliant generalist who sees the big picture to communicate and lead, someone who can speak both languages (tech and business),Often it's someone with a strong tech background who has grown up in an entrepreneurial family or lived in an entrepreneurial environment long enough to absorb the language and a tacit understanding. Paired with a co-founder who has deep, specialized, world-class expertise and a world-class engineer who loves to code, that's a strong team.
Don't worry about scaling to 10,000 employees before you've even begun. That will be a great problem to have when the time comes, and by then you'll the funds to hire a team of MBAs. You outsource your legal and accounting to specialized firms. When you're ready to raise funds, find a good startup attorney to set up the corp, and they'll who the good accountants are -- ask them to recommend. Until then, focus on your team and the core problem you're trying to solve, understand it from every angle -- from the perspective of multiple domains -- until you see the way it all aligns.
Beyond that, read Paul Graham's essays, absorb the Startup School lectures, and read Zero to One:
* http://www.paulgraham.com/articles.html