Are you going off actual measurements? Or the Homalo in game. And also, I said it might be different where you are basically because one, the colder temperature would make it inefficient to have animals roaming around for most of the year and 2, well. I’d imagine the zoos wouldn’t be particularly huge or as well funded. And if you’re going off the very flawed “extinct animal” excuse. The same can apply to you, how do you know it was aggressive? For all we know, Homalo could be more docile then your average puppy. And a dome for all we know could be decorational. Ceratopsians have had similar ideas, big horns and frills that were ultimately not used for much more then display. At least for those animals they have the size and fossil evidence to prove they could be more aggressive. Homalo has no such proof besides a dome that even if it was used as a combat tool, would probably be only used by males in mating fights.