A lot of combat training includes make shift tourniquet training. You can learn everything you need to know from a youtube video. I mean honestly you can make a tourniquet out of just about anything. While carrying one isn't a bad idea, I get sick of all the "just in case" gear i.e. sat phones, extensive med kits, etc.
Now if you are worried, carry that shit. Otherwise, just be smart.
It says in the top of the pack for archery season. Other times of the year it may be elsewhere. I've only applied a handful of tourniquets but when time is a concern I don't want to be looking for supplies to make one. I'd rather use a pressure bandage if given the chance and if it will do.