David,
It sounds like you need to work with an HR consultant to form a staffing plan and Org chart, which will not only address how to get the most efficiency out of your current talent, but also help to create a plan on talent acquisition and position importance moving forward. As start ups evolve this is one of the most frequent things I see them struggle with. Because in a young company employees wear many hats (unavoidable), you also need to form job descriptions that show what the most important hiring characteristics are to the positions you plan on filling. This will give you the best shot at hiring the right people the first time, and retaining them as you grow. Turnover in start ups can be a very costly issue. If you would like to hop on a call to discuss further I would be more than happy to help.