The role of the CTO depends on the context. Sometimes you lead, sometimes you just facilitate. Sometimes you focus on technical quality, sometimes you focus on business objectives. It all depends on the balance within the company and the companies objectives.

Bottom line is that you base your strategy on what the company needs, not on some abstract notion of a good CTO. The only consistent objective is to make yourself as superfluous as possible by creating a balance between engineering quality and business objectives that maintains itself without constant management interference.