You could also argue that my rule was self-protective: over time, a hypocritical leader becomes vulnerable to being replaced by another, more walk-the-talk leader. Believing in your own principles is necessary, but not sufficient. You must also do as Senghor did and transfer those principles to your team in a way that sticks. Depending upon where the team is to begin with, this transfer may be a relatively minor effort or an immense undertaking. But it is critical, because it not only establishes the culture, but cements you as the leader.
