How much equity for being employee #1? I will not promote

After selling my company and taking some time to evaluate the market, I’m ready to start my next endeavor. Manufacturing domestically and selling to a small, tight knit industry where I have many contacts on one side of the business. About a $3M investment to start which I will likely finance. Could scale to $20M in revenue very quickly. So here is the question. I have someone who I would like to partner with who comes with a lot of experience on the side of the business that I am weak in. They could likely