You are thinking way too deep into this.
They just made a generic system and slapped it on top of all the animals and couldn't be bothered to tailor it to specific animals because the devs volunteers simply don't give a ######.
This mentality applies to the whole development of Wurm. Just rush something out so that the simps will eat it up, fix some minor bugs, and move on to desperately rush the next update out "on time" with the handful of volunteers working on the game. Of course delays happen since the volunteers can't work full time and have no contract or obligations to do so, thus the whole "real life issues".
You don't see that happening with other MMOs. Then again, other MMOs have proper, in house, contracted, full time, employees whereas i believe codeclub has less than 5 actual employees according to tax documents that you can check online. Even Keenan (the server guy) is a 3rd party contractor.
If they just hired some random outside party who never played and most likely never heard of Wurm before to develop it for VR (which they 100% did) then lord have mercy on this game. Hell, most experienced VR devs out there have no previous experience on doing VR for MMOs, so what possible team could they have hired with such a small budget when the company is/was losing money? The logic here is mind boggling and i have truly never seen such out of touch developers/company. I'd rather see Activision Blizzard get their hands on Wurm at this point.