PIE Twins, Kastor, Haddingr and Saint Cosmas

In The Origins of Greek Kosmos and Latin Mundus, Jaan Puhvel:
"Now there is another Indo-European verb with similar meanings, viz. *kes- seen in Old Church Slavic c^es^o 'I comb', cesati 'to comb', kosa and kosmu 'hair'. Other cognates are Russian kosd, Lith. kasa 'braid, tress', Old Irish ci:r 'comb' (< *kesri), and Old Norse haddr 'long hair' (< *hazdaz < IE*kosto´-). Here belongs also Hittite kis(s)ai- 'comb, card' (< *kesaye-) which is used of both humans and sheep."

My point is... is there any possibility of Greek name Kastor be related to this root? Curiously and (maybe) coincidentally, twin saints Kosmas and Damianos (Cosmas/Cosmo + Damian) have names with "dioscuric-asvinic" reminiscences: Damianos, if related to dam- "to tame" (Dioscuri/Asvins as horse-tamers), and Kosmas, if related to kes- "hair, long hair, braid, tress". Compare them to Germanic tiwns *Hazdingo:z, from *hazda-.

Joao S. Lopes
Rio