If you are going to rely on other people's information and research, you are always going to be at a disadvantage. Family stories may be interesting, and sometimes contain at least a grain of truth that may point you in the right directions, but often little more than that. Other people's research may very well be faulty also. I would guess at least half of what you come across on the internet, such as the LDS site, are problematic (other than the public records that you can access at ancestry.com and such places.) And just because you see it on more than one site isn't conclusive of anything. Misinformation repeated 100 times is still misinformation.

There really is no substitute for original research. I would certainly verify everything I came across from second hand sources before spending thousands on tartans and other such clan paraphenalia until I was assured beyond a reasonable doubt that I had a descent from the clan.