In my experience, one driven, completely bought-in and trustworthy cofounder with a business and sales background instead of engineering can make all the differ

In my experience, one driven, completely bought-in and trustworthy cofounder with a business and sales background instead of engineering can make all the difference in the world. To be in business, not just raise money and spend it, you need someone who thinks about revenue and sales the way you obsess on technology. To retain this kind of person, he/she is going to have to be a real owner the same way you are and live and die with the business. A stock plan vesting over X years, allowing for the usual dilution and acceleration clauses, along with very substantial part ownership: somewhere between 1/3 and just under 1/2 of the original shares, is what "co-founder" means to me. An idea and even a MVP demo are useless without sales, marketing and operations if you actually plan to run a business. However, if you get too many high stakeholders you will probably have enough negative attributes collectively that nothing will ever get full buy-in, and worse, you risk creating factions in leadership.