The more I think about it, the more sense it makes that he had three kids. Imagine it; there's essentially 6 Chakra affinities, and 6 "Paths". It makes sense that each child would inherit 2 Chakra types from him; the Uchiha inherited Fire and Lightning (Blaze), Senju Earth and Water (Wood), and the daughter Wind and Ying/Yang. Naturally, as time progressed, not everyone in the clan keeps those exact affinities as they mate with people outside the clan; but the Uchiha still has a strong Fire affinity, while the Senju has a strong Water affinity, and the Uzumaki has a strong Ying/Yang affinity or Wind affinity (not much are known about them other than their sealing techniques, really).
All non-elemental techniques (such as Shadow Clone) are based on Yin/Yang release, and Naruto excell at those, too. Besides, the entire Uzumaki clan excelled at sealing techniques, all of which are based on Yin/Yang release.
Then again, Uzumaki means "spiral" or "whirlpool", but tornados are also spiral-shaped. Their clan seal is also that of a spiral (similar to the first Uchiha's eyes):
and is also the symbol of the classical Uzumaki-seals:
Which also has what looks like Uchiha-like Tomoes.