This is why a methodology, whether it is agile, waterfall, or some bastard spawn of RUP, is not enough to direct a project. What you need is someone who can tak

This is why a methodology, whether it is agile, waterfall, or some bastard spawn of RUP, is not enough to direct a project. What you need is someone who can take on the role of project manager. A project manager has many roles, but one of the most important is to figure out which bits of the chosen methodology do apply, and which don't. There is no such thing as a "best practice" - only a "good practice within a certain context". The PM's job is to figure out which practices match the current context, and monitor them as the context changes and certain practices drop out (and others drop in). What you end up with, if you have a good PM, is a unique methodology tailored to your specific project, which is the only sensible thing, since all combinations of project and project team are, in fact, pretty much unique. It's worth adding that the PM doesn't need to be full-time - but I'd say that even on a 2-3 people start-up dev team you need at least one person who's experienced enough to take on that role.