No, the Celtic Scots did not descend from the Scythians. The Scythians were speakers of the Iranian branch of Indo-European. The Celtic Scots were speakers of the Celtic branch.
I didn't mean they literally descended from the scythians, but that they both derive from the indo-europeans from the eurasian steppe, and so cultural memory of this could influence the story the original poster was referencing. Although I realize my wording was pretty terrible, so it did sound exactly like I was saying they were descended from scythians. My bad.