Let me try to paraphrase:

I don't trust anyone as much as I trust myself to be competent and really try hard to get things right. I can see that if I followed any rule I can imagine to disagree less with people, based on their qualifications as seen by third parties, there would be cases where I'd have to agree more with claims that to me are obviously wrong. So I don't follow any rule, I just do what seems right, and damn it, doing that is what seems right to me - and it seems to work!

The problem is that a great many other people feel exactly the way you do, but when you disagree with them it is clear that at least one of you would be more accurate by disagreeing less. So by more carefully analyzing these kinds of situations we should be able to identify who to advise to disagree less in what kinds of situations. Your passion here shows just how important it is to do this and get it right.