That's part of the challenge (and fun) of building these kits. I work in an ED now, but I have spent time on ambulances and the difference is significant. You really learn to make it with a lot less. Even less than that with some private or tiny services 😂 I also try to make custom or multiuse things to save space/weight.

Another challenge is that "needs" are often dictated by chance. All we can really do is use data and critical thinking to do the best we can. I've had people code or become critically ill in the ED (arguably the best place to do it, and mine is at a major city hospital) and still die. I still have to improvise sometimes even in that environment due to shortages, rare cases, etc.