You wonder if 'Tosk' might have been set up by the Dominion in order to pacify and distract the population, and desensitize them to bloodlust.
IIRC, the Hunters are indeed members of the Dominion (a Hunter was supposed to take the helm of the Defiant
in "Broken Link" and guide it to the Founder homeworld, but this got changed to a Jem'Hadar at the last minute). The Tosk were bred by the Founders as gifts to the Hunters. You'll notice that not only do the Tosk sort of look like Jem'Hadar, but their shrouding ability is identical...