The Grimtotem are anything but friendly, yupp. They not only happily murder Night Elves whenever they can, but also other Tauren. Although that was somewhat toned down later on. Honestly, I’m not even sure how the current situation is, since now everyone seems to be turning into my little pony caricatures.
When looking at regular Tauren, they marched into Darkshore and helped spread plague all over the zone, destroying it. However, lore-wise, BfA is so messed up that it’s hard to consider the expansion as canon.