I'm not trying to flame your project, but merely impress upon you that you have way too much Risk to realistically succeed at this project the way it's being handled right now.

If you are taking the role of the Producer and you believe that my words are true, then I urge you to use your powers and follow my advice:

1) A big chunk of the GDD is not a complete design. You should have every section of a GDD complete, even if in outline form, before you hire even one person on the team. Worrying about how the code is going to be laid out is an Implementation routing, not part of the Analysis and Design phase that you are under and betrays how unprepared or un-organized you are from day one.

2) There is no sense hiring 27 people at the beginning, especially without a fully fleshed out design. Start with a few core people doing programming and artwork and then build up from there. This idea of mass-hiring of people have sunk many a game dev studio with actual budgets. As this is a pay-after-publish project, you'll have even larger problems.

3) Managing a remote team is worlds different than managing a military project. People that sign up for the military have a natural team mentality...someone leads, I follow. People that do game development have a natural rebellious mentality...someone leads, but why should I follow? Keep this in mind for while you have had success in the military, this can acuatually be detrimental to managing a game dev team.

4) Read "The Game Producers Handbook" by Dan Irish to get a feel for what is expected of you in a game development Producers role.

5) Follow established Software Engineering practice. I recommend following the Cascade non-iterative approach for now which means you do Requirements, Analysis, Design, Implementation, and Testing in that order. Do this for the demo (NOT the full game) to get a feel for what you are up against and to give you team members experience in working together and the confidence you so desire.