Hi Michael
Sorry I didn’t see your video as it required signing in, which I didn’t particularly want to do. However, I can make a guess at the scenario.
Male hogs in particular can be very intolerant of other male hogs being in their personal space, wherever that happens to be. If females or food are included in the scenario, that may increase their intolerance. But I suspect more aggression may happen at feeding areas, than elsewhere, because that is where hogs are ‘encouraged’ to congregate. But hogs do not have territories which they defend, as such – they have ranges which overlap with the ranges of other hogs.