Exactly, if they are distant blood relatives to the Senjus then it means they do not share the same Apical Ancestor (Ashura) for if they did they would be close blood relatives, ergo, the Uzumakis did not descend from the Younger Son
Incorrect, it is substantiated by Manga Facts, Genealogy and Biology:
Ashura's descendants: The Senjus do not share the Uzumaki trademark red hair:
You must be registered for see images
You must be registered for see images
In fact, Ashura's hair was depicted as black in the anime:
You must be registered for see images
And for your enlightenment: red hair is the most recessive hair color in humans, the best example in the Manga would be Naruto, mix red with yellow and he turned out to have yellow hair like his father Minato. The pure Uzumaki blood is from an original undiluted progenitor gene.
There is no possible way that the Uzumakis descended from Ashura, to insist that contradicts the Manga and basic genealogical and biological principles.