When you’re cold and wet and in desperate need of warming up you need a dependable way to get a fire started. The Gerber Bear Grylls firestarter is simplicity itself with one end providing a ferro rod to create a spark and the other a metal striker. There’s a lanyard running through both ends so you don’t lose track of anything and a powerful emergency whistle on that same lanyard that will allow you to signal for help. The whole thing tucks away neatly into a waterproof storage unit that measures a modest 4 ¾” in length. Mastery of fire is what separates us from wildlife. This piece of fire-related survival gear can ensure you walk out of the woods at the end of your ordeal.
Each type you listed (save a couple) will have its uses in a community (group if you will), generally having a small trusted group with each having several skills in the various fields (prepper, homesteader, and survivalist) I believe would be an effective team, though as each group works together would it not be best to ensure that each has overlapping skills in case of injury, death, or other reasoning they can not fulfill their duties?
Say you're at work and a terrorist attack occurs. Roads are closed to any and all traffic but you only want to get home - even if that means walking. You may not want to grab your full on family pack in the car or you may not even be able to get to it. But you just want a light kit to get you through. How far is it to get home from wherever you may be? This get home kit should provide for 1-3 nights of traveling on foot till you make it home.