Because it would get im the way and be uncomfortable to wear. I don’t mind if they’re on the smaller side if it is for barbarian nations, but I’d also like variety in plain helmets as well. You can see things sticking off of armies such as feudal japan or the winged hussars, but it’s always on their back. This is because the weight doesn’t affect them too much and it doesn’t hinder their movement, because it’s on their back