He's extremely ad-hominem and paints that picture of that "dysfunctional team member" (read "asshole"), and his whole idea of an organization basically boils down to saying that you don't want an asshole in it: Don't risk hiring an asshole, even at the risk of a huge false-negative rate in your hiring decisions. Cleanse your organization by instituting a witchhunt for assholes and putting them through the wringer to make sure they're reformed or fired.
Contrary to what Lencioni preaches, I believe that management is about selecting teams comprised of individuals who know how to do stuff, telling them what to do, and giving them incentives to make sure they actually do it.
Lencioni seems to think a manager is like a spouse who cares primarily about who their spouse is, or like a mother who wants their child to be a certain kind of person behaving a certain kind of way.
This ad-hominem level is precisely what you learn to steer clear of, if you've ever taken a course on conflict management. Focus on the issue, not the person. ...it's also borderline illegal in certain jurisdictions. For example in German employment law and constitutional law there is the idea of the "allgemeines Persönlichkeitsrecht" which says that basically, while you can discriminate between employees on the basis of competence and what they accomplish for you, you can't discriminate on the basis of who they are or what kind of person they are.
I once worked in a workplace where managers high up the ladder were very fond of Lencioni's writing, and pushed the philosophy on middle management too. The place just felt unprofessional and cult-like. I felt I was constantly under pressure to prove that I wasn't an asshole, and whenever I'd disagree with a manager, it was hard to even just have a meaningful conversation about the topic of the disagreement. Instead, the conversation would immediately turn to this unspoken accusation that I might just be an asshole for disagreeing in the first place, and now I needed to prove that I wasn't one, or else my career would be deeply in jeopardy.
I strongly advise reading Lencioni, and then thinking long and hard about how not to fall into the trap of thinking about organizations the way he does.