It depends on your goals as an organization paired with each team members career goals. Are you attempting to give them a map that is suitable in consulting, enterprise, startups or just a generalized roadmap? You are here (x) role today and would like to be there (z) in a specific amount of time. I think many people get frustrated with consulting work so they have a tendency to go client side (whether start up or enterprise). I think you should be transparent and accept that as reality and map several paths both internally and externally. I think that would benefit your organization culturally and reduce churn. Incorporate existing technical/business skills and map each of those tracks out, showing how they are beneficial to the consultant/developer over the course of their career. Just a few thoughts.