A mule or a stallion for a church man?

I read this interesting paragraph in an article on church planting (http://www.acts29network.org/acts-29-blog/ten-qualifications-of-a-church-planter/):

We prefer the men in our church to be mules. A mule does not act like a jackass & they are able to carry larger loads & endure longer than a horse. They are tamer than a jackass but do not seem to want to run like a stallion. I think many pastors prefer a mule to a stallion. Stallions are designed to run & not be penned up in a stable. We are generally afraid of stallions because we are afraid of our own masculinity, our leadership, & our "importance" to the Christian community. We are afraid that the stallion will steal our oats & our affirmation by "our" people. Since our own fathers did not affirm us, this is seen as a threat. We value Steady Eddie instead of Daring Dan. Christianity is a radical following of Jesus. The problem with being a mule is that it is almost always sterile.