Over my career course as a consultant-type person, I've developed some patterns for dealing with irrational pointy-haired boss types and the technical sycophants that sometimes accompany them, and I've passed these on to friends for their own use. One has recently been used successfully and so I thought I'd document it here. Fortunately, the friend who used it also gave it the memorable name that patterns are supposed to have: "The 'Let Them Say Any Crazy Shit They Want' Mind Trick Pattern".
Here's how it works. If you disagree with someone on a technical point, and you know you are right and they are wrong (either from misunderstanding the problem, politics, underwear too tight, whatever), let them make whatever claims they want about their solution. The executor of the pattern calmly reminds them that his way is better for these calmly stated reasons. Let the arguer point to a phantom requirement, or phantom performance problem, or any other specious claim, and the executor remains calm and points out why his way is better. Repeat this pattern until everyone is saying that the executor's way is better. It takes quiet confidence, zen-like calm, and unshakable conviction, but it works. The recent application of this pattern by my friend (in conjunction with another pattern not of my devising) took 8 man-days but, in the end, they are doing it the right way.
This pattern only works if you are technically unassailable, and you have to concede if the arguer ever does make a salient point. However, the zen-like calm in which it is delivered still keeps lingering resentment over disagreements to a minimum. To be used sparingly in situations where nothing else seems to work and you are being asked to do something stupid for no good reason.