As Scotus stated above, take anything from Familysearch, or Ancestry with a large grain of salt. As a research genealogist, I have found that Ancestry trees are about 60% wishful dreaming. Use them as a guide and then hit the primary sources. For more insight into the "Royalty" stock, read Gary Boyd Roberts Royalty for Commoners, it is a well documented treatment of the common lines that most Americans share with Charlemagne. He has treated the Robert the Bruce lines in several articles in the New England Historic Genealogical Register, a quarterly publication on documented genealogical research.
Please do not let this dampen your enthusiasm for genealogy. It is an addiction that equals that of kilts, but is more time consuming, and over a more difficult path. Somewhat like my learning the Bagpipes has become.
Slainte