Seeing as you seem to want a proper answer I'll try to explain it. Though I'm no expert on the field by a long shot I can say that this game SUFFERS GREATLY from it's bad dark times. It's old, it's out dated and it was built on a dumpster fire. The devs hide this SO VERY WELL that it's easy to forget. As such it does things in ways that are not great but are stuck that way cause that's the core of the game.
Example, your character doesn't "really" have a perma body. The game works on a system of "Replace X with Y" so your character's torso and arms and legs and so on "are" whatever the glam or gear appearance you use. So when things don't fit right you can get funky outcomes. Tis why some tops give you bigger or smaller boobs, they're not laying that on top of a model, they replaced your torso with a different model.
What am I getting at? Welp, the Hrothgar have an unique customization option. Something that no other race has. They have the ability to change the color and pattern of parts of their arms/ torso/ legs. Given how this game works, that's a whole lot of stuff the game has to account for when looking at how gear interacts on them. Where does all that space and processing come at the cost of? The only character option that other races have that can be altered greatly and has tons of different looks and "patterns". Hair. Hair changes shape a lot and anytime you wear a hat most hair models change a good deal.
Hrothgar do NOT have "hair", they have a character creation option (Manes) that can be slightly altered with face features tab. The devs had to sac hair to make fur patterns a thing cause this game was not built on a system to handle that kinda freedom with body color and patterns. Just like how this game wasn't "built" to have butt customization so the devs gave us a big ass glam to fill that ass void. Game wasn't "built" to have body tattoos ... so we get a few glams that have tats built in.
Game wasn't built to have a system for beast heads like that to have helms that fit them so unless they can insure no part of the face will ever be visible they don't give them a helm.
With Viera it's a different story where their ears are to blame. But yeah, Hrothgar are a race that required letting a number of things go to work in this game the way they do. I'm hella grateful for them as I think that regardless of their limits they bring a ton of creativity and life to this world. It's perfectly possible to make them have all the bells and sch next time in a new MMO, just not this one.