Perhaps he can be a sort of superintendent.  

@Brad TrauthHey Brad, shoot me a PM I’m a traveling superintendent but trying to set my self up to build my own rentals in Cincy

He said his markup is transparent and has things like 10K superintendent fee.

I have construction experience (been working for a big GC as a superintendent) however we are pretty new to REI business, and looking forward to connect with you guys! 

I've been a field superintendent at GCs, and now I work on the product/data team of a construction cost data company.

What does one do when they're not big enough to have a Superintendent, but  just big enough to have to register with the city?

I would also provide the expertise and management for anything needing a contractor as I'm a former residential superintendent and current commercial construction project manager.Part of the reason I'm interested in this, besides growing my portfolio is taxable income reduction.

If I were you I would figure out the responsibilities of the partners and the time they will devote to the business and then search for similar job offerings in your area and use that as a guideline, for example full time project superintendents in your area make between $35-$40 print out job listings and put in a file, and pay accordingly to the the time they plan to devote to the business.  

Do you just rely on a field superintendent on your staff to be the bridge between corporate office and the subs who don't know how to use a computer or email or whatever?

No, because one of my superintendent/employee foreman worked for a foundation repair specialist, it's a niche market.