*shrug* The word "Titan" conveys something more specific to me than just giant, and I would hardly consider the movie canonical, but I still don't know anything helpful about the original question. Even if you consider Titans to be canonical, I still am unsure about the whole Crom vs. Titans as being canonical, the latter of which I definitely don't see as canon.
Still, to me (as an author), word-choice is important. That would be like writing a story set in Africa, and putting jaguars there - because a jaguar just a generic word meaning a large predatory cat that lives in jungles, right? Maybe we could shoot the jaguar with our shotgun and tell the story, but call the shotgun a rifle - because we all know that a rifle is a generic term for a
long, two-handed gun with a stock, and not a specific type of gun.
Anyway, that is neither here nor there. I don't know anything about Crom vs. the Titans, but if you want to know about Crom vs. the Giants, watch the first few minutes of "Conan the Barbarian."
Maybe he is referring to the Giant-Kings (first mentioned in "The God in the Bowl" IIRC), but I don't know that they fought Crom.