Arranvin

Hello folks. I was wondering if someone with more experience of the game than I have can answer a couple of questions for me. First off, how is an animal companion's proficiency with stealth calculated? Do they become more stealthy when you put points into your ranger's stealth skill, or is the value determined by the animal companion's level? Secondly, are animal companions meant to take knockout injuries? I've been noticing this since I started a solo PotD run (3.01), given how often my wolf is tanking for my woof elf. It seems a bit odd given that animal companions are essentially unkillable as long as their ranger survives but if it's intended fair enough. Thanks for reading!