Ideally, a startup developer needs to be a rockstar. This means they need to be able to be self-sufficient in many ways, since budgets (fiscal and otherwise) are extremely tight. They need to be able to set priorities and communicate changes quickly and efficiently.
That said, once a development team reaches a certain point (in my experience 3-5), it needs a decision maker to move forward in times of need. This technical lead usually will take the role of CTO, but doesn't necessarily need to. A Chief Product Officer (a lead Product Manager) can often fill this need temporarily, but will be leaving a large gap unfilled on the technical side.
If you're not technical and are hiring outside help, hire help that offers this leadership for you. An interim CTO or project manager on the consulting side can definitely help things stay on track. Note that the more layers of communication you add will definitely slow things down and add some confusion.