Is it intended for mammoths to be exceedingly easy?
One log on the top of a cliff and I can block its snot. If I attack between snot attempts it won't hit me. Even if it does hit me, it does not matter since it never lowers its openings. Like at all. I can sit there and lower mine and get back to business. Bears at least lower their openings when you sit there gaining IP on them. Mammoth is like, oh you opknocked me 3 times and I'm at 100% opening, hurr durr let me just sit here spitting. Cleave or sting, it flees, reaggro, cleave or sting, occasional opknock to keep him on high openings, rinse and repeat until dead.
If this is intended, so be it, but I find it highly strange that it won't lower its openings even a smidge.
I have more thoughts on the nonsense palisade trap method to kill them but even that would be less of a cakewalk if the mammoth was lowering its openings. Or had a ranged opening attack like the bear.