Is that an actual question, or an oblique way of suggesting that the thesis of "Well tended gardens die by pacifism" is promoting a form of Truth-Guardianism, and therefore contradicts the thesis of "Guardians of the Truth", and therefore perhaps both theses are flawed?
If it's the latter: yes, yes, very clever.
Assuming charitably that it's the former, my two cents about how they relate:
WTGDBF predicts that where local community norms N1 differ from global norms N2 there's a tendency for N2 to displace N1 whenever the local community interacts with the larger world, and suggests that if I consider N1 superior to N2 I have a moral responsibility to counteract this tendency, which sometimes requires violating N2.
GOTT suggests that certain norms which involve punishing attempts to challenge or question certain ideas regardless of how novel, well-formed, or carefully reasoned those challenges/questions are, are bad for communities that embrace them, despite being well-protected from outside norms.
Combining the two suggests that when I choose to defend my local community norms against corruption by outside norms, I also have a moral responsibility to be right about the superiority of my community's norms.
There is some difference between group ideas and group norms, although sometimes these two overlap. There is also a difference between challenging group ideas, and breaking group norms.
An example of a group idea: "It is reasonable to give million dollars to an organization that will freeze your head when you die, because someone might scan your brain and make a machine simulation of you, and it will be really you."
An example of a group norm: "We should refrain from political examples, personal attacks, irrational arguments, etc."
An exam...
Like any educated denizen of the 21st century, you may have heard of World War II. You may remember that Hitler and the Nazis planned to carry forward a romanticized process of evolution, to breed a new master race, supermen, stronger and smarter than anything that had existed before.
Actually this is a common misconception. Hitler believed that the Aryan superman had previously existed—the Nordic stereotype, the blond blue-eyed beast of prey—but had been polluted by mingling with impure races. There had been a racial Fall from Grace.
It says something about the degree to which the concept of progress permeates Western civilization, that the one is told about Nazi eugenics and hears "They tried to breed a superhuman." You, dear reader—if you failed hard enough to endorse coercive eugenics, you would try to create a superhuman. Because you locate your ideals in your future, not in your past. Because you are creative. The thought of breeding back to some Nordic archetype from a thousand years earlier would not even occur to you as a possibility—what, just the Vikings? That's all? If you failed hard enough to kill, you would damn well try to reach heights never before reached, or what a waste it would all be, eh? Well, that's one reason you're not a Nazi, dear reader.
It says something about how difficult it is for the relatively healthy to envision themselves in the shoes of the relatively sick, that we are told of the Nazis, and distort the tale to make them defective transhumanists.
It's the Communists who were the defective transhumanists. "New Soviet Man" and all that. The Nazis were quite definitely the bioconservatives of the tale.