Alright, I'll play devil's advocate. I'm not entirely convinced and the most of the examples except the belt plate are about a century late. Decorative figurines aren't very helpful either. The only thing that came close is the second last image you linked but there are women watching it, which clearly identifies it as a tournament scene. And even there (in last and second last images) look at the proportions: 1 knight with horns out of hundreds or out of 8. To me, this only proves that sources used horned helms as a distinctive sign, which means they were extremely rare out of tournaments. In all the images you linked in your second spoiler, infact, you see one knight with horns, all the others without. The first is, likely, a battle scene. Though again, there's one man with horns, one with what's likely a wooden crest, the others' armours are all as slick as possible.
The first image of your first spoiler is a very famous helm that I've seen several times but, correct me if I'm wrong (no clue about it, in all honesty), those horns are not of the same material of the helm, nor forged on the same piece; that's something I've been mentioning all along. They probably used lighter materials that could more easily be knocked off then stuff that could set them off balance. In modern reconstructions and drawings in particular, you always see metal horns nearly twice the size of the man's head. That's simply ridiculous as a great helm on its own already weights an enormous amount. Who would add more metal to it? Surely they built their crests with cloth, wood or I think they even used paper mache. But iron? Steel? Why? So that every slash that misses the helm and hits the horns scramble your brain and makes you lose your footing? I just don't see it happening.
There was a tendency to have adorned helms on seals, but again that's hardly a proof if at all. Once again, to me it only means they used the most badass stuff they could come up with when they needed to show off and stand out from the crowd (again, tournaments and probably one's seal). Otherwise, as little target as you can offer works for them as it works for us, I'd guess. This all assuming that XIV century's sources didn't idealize earlier knights and just exaggerated the crests to make them more distinctive and interesting to look at. Art is still a stylized depiction of reality, after all.
Guess I'm just overanalyzing the whole topic, though I need to see the "smoking gun" here to truly believe we'd see plentiful horned or even crested helms on a medieval battlefield. It just sounds far too impractical to be adopted. Reminds me of the argument against mail, stating arrows could puncture it with ease. Then again it lived for about two thousands years in various regions. I'm probably wrong, though I can only see paper mache or at worst wooden crests being in wide use. Beside, most sources show relatively simple helms for the vast majority of fighters, often all of them except one.