Ossetians are linguistic and genetic descendants of the Alans, a iranic people.
Their language is the most similar surviving language to that of the ancient scythians.
en.m.wikipedia.org
Where did you took the data that ossetian have more R1b than R1a?
They are massively G and J2 anyway.And Y-dna actually has not a strict easily markable correlation with the language spoken or autossomal dna, don't let haplotardism convince you otherwise.