Cossacks kicked Turks out of Azov (key defence on Turkish border) and successfully defended it for 5 years against much superior Ottoman force and left the town on orders from Czar Mikhail Romanov of Russia who didn't feel it was worthy cause for a war as Russia was too weak at this point to make plans for Northern shore of the Black Sea. It takes a bit more than "Raiders" to do it, don't you think?
Precisely. And as I said, there was also the Cossacks, with their only allies being the equally "raiding" Tatars and the Ruthenian peasantry, who were militarily pretty negligable, were able to hold out against Poland for six years, and longer after the Russian intervention.
Not that separate back then. Both hosts considered one another to be "brothers" and worked as united force at Azov, among other things.
Certainly true, but their were some differances, in their military styles as much as anything, and that's what Nikephoros seemed to be referring to.
Black Sea cossack host are direct descendants of Zaporozians who were relocated there by Catherine the Great.
True (I implicitly acknowledged this when I said that the Kuban cossacks, succesors of the Black Sea Host, were originally Zaporozhian). I wasn't referring to their origins, but rather to the existence of an effective Cossack sea-force. Anyway, turns out I was mistaken: it was the Azov host, who merged with the Black Sea Host into the Kuban Host after the Caucasus War was concluded.