This thread is not only going pretty far off topic, but even the off-topic subject is getting pretty confused.
It started with the suggestion that a bow string be included in a survival kit. I think that this would be a waste of time anywhere. I used to make and shoot my own self bows, stalked small game with an air-rifle (same sort of ranges a basic bow works over) and had a great deal of interest in US bow hunting having family there and friends that hunted. A bow is easier to make than the arrow is. Bow hunting isn't legal in the UK, so pointless addition in the UK. Active hunting is a very poor use of time and energy if you have become lost. Passive hunting, where you carry a weapon as you go on the off-chance of a shot is better, but a bow and a set of functional arrows is still a big investment in time and energy. I have yet to meet anyone (other than bushmen in Namibia) who maintains the skill level to reliably stalk, hit and kill game using a bow and arrows that they fashioned in a day or so out in the woods. I know such people exist, but I have never met one, so I hope I can be forgiven for thinking that this scenario is more fantasy than reality. The bushmen were not all that accurate with their bows, relying on very good stalking and poison.
The conversation then turned to dangerous game, and a confused mix of hunting and hunted. This is a big step away from the reason to pack a bow string in a survival kit. Even with skills, and an expert level bow and arrows, you would not generally go trying to stick an arrow in a large predator for food. This makes no sense outside of Hollywood films. Sticking a field made arrow from a field made bow into a charging griz is a terrible idea, even if you have the skill and nerve not to miss. The gear is very unlikely to have the power and strength to penetrate, so IS more likely to just annoy. There is a huge difference between stalking an unsuspecting bear and planting a 600grain shaft from a 60lb recurve through its chest from a good broadside angle, to poking one head on with a 400gr dogwood sucker tipped with chipped stone shot from a low efficiency 35lb stick bow.
Bows and arrows are complex compared to slings, spears and clubs. They are more complicated to make and require more skill to use well enough to be effective, especially under stress.
Most of us can go a good long while without eating, a lot less without water or shelter, so kits should address those needs. Fish hooks can be set as unmanned traps, no additional energy, and very little skill although in the UK though I can't think of anywhere that you would need to catch fish to survive. At sea, its another matter! Worth using stainless hooks?Snares need to be set in numbers and packing enough wire for just one or two won't keep you fed. Better to not eat and let your body adjust.
Anyone read Mors' booklet on survival kits? his fits in a big billy can and is not pocket size, but it allows for you to have shelter, fire and water in deeply cold boreal forest. Kits need to be tailored for where you might need them, which is the problem with commercial kits which are as much about selling as saving.
I know someone who used to work for BCB and what they said about them would make me extremely reluctant to put faith in any kit they put together. As an example, at the time he worked there, the potassium permanganate used in kits was fire retardant to aid packaging processing, while being marketed as being suitable for fire starting.