that sort of complication is exactly why use of horns in combat could be just about as hard to master as any other weapon.
... I mean, sure someone could grab them, but that would just make it a wrestling match, and if this caparii was strong enough to consider headbutting as a viable attack, they're probably strong enough to throw you to the ground if you grab those horns. or something. I mean, if its an earthspawn grabbing horns, but like, then it's a wrestling match and like, yeah.
I need to find videos of people trying to prevent horned animals from ramming them, but that doesn't seem like something a weakling would be able to do.
and like, woe be it if the horns happen to face forward. now its a goring weapon.
Presumably, you watched people try and grapple large bovine-like creatures? Deer, cattle, bulls, etc? Well, There is one main thing that differs the most between Caparii and bovines. The bovines have thick, muscular necks to support their weighted horns. Their horns are thicker for their fighting reasons. The horns consist of two parts. One part keratin (outer horn) and one part bone (the live bone/marrow inside the keratin). If those bones break, it causes bleeding. Onto the main part. As for grappling a Caparii. Their necks can only be so muscular and solid to an extent. To look at a bull, and you see almost no transition from neck to main torso. On a human-like being, it is a drastic change. The force and control of a completed grapple/hold could most likely
easily retain the limited strength of the human neck. Of course, it all depends on the different statistics. (The two people). I don't see the horns breaking by any bodily force, but I don't think that keeping a Caparii at bay by grabbing his horns would be too difficult of a task. Again, it differs on the people. Human necks are a fragile thing.
I will consider the Greathorns, too. They re told to have larger horns than the other gene-pool. It would be realistic that they sport larger necks to hold up their horns, but I don't think it's anything outside of the human limitations. Again, I don't know specifics, as the public lore does inform me enough.
As for hooves. From what I know, goat (Caparii) hooves are cloven. The given digits they have are almost fingerlike. They have soft innards, with a strong hard shell outside. The mass of Caparii hooves are rather large compared to other mammals, in theory. (Correct me if I am wrong). The lore says that Caparii legs are very strong. So, yes, their legs are a viable weapon in wrestling, and I would
not want to get hit by a big brawny Caparii with their hooves.