Hi Susanne,
I agree with what you are saying. As Cynthia said, clues are a wonderful direction to pursue. We should not use them to link to an individual without proper documentation.
So many times extended families had multiple common given names and have been attached to the wrong family because every child wanted to name one of their children in honor of a father or grandfather. In addition, I've even found some families that have named multiple children the same name as of an earlier deceased child, although the last is primarily in Europe.
I too spend time at FS un-linking and re-linking, but only when I have the paper documents to verify lineages. I've found many discrepancies in Ancestry too and even on the DAR website I've found errors.
We are all searchers and we can all make errors.
One of the surest ways to find common ancestors is with DNA matching and triangulation.