In many cases, you can wind up trying to define in the abstract, and hence lock in, roles and relationships that are by definition still not settled.

The example given in the original post sort of proves this point. The OP makes "developing and managing of the software development" and "managing of the tasks" CEO responsibilities. It's not clear how those terms are defined, but it arguably suggests that were the CEO to focus on biz dev instead of coding or if a CTO decides to prioritize one bugfix over another without consulting the CEO, someone is now in breach of a legal agreement.