Ok prepare for RANT here....
I am a remote medical person who also works at a very large urban hospital that gets plenty "field repairs" gone wrong.
Everything below is based on REAL experiences of treating people in the field with little to nothing and dealing in the ICU with all the infections after.
First before you worry about the kit what is your plan for when it all goes wrong? InReach, Spot, Ham, Cell, Smoke Signal.....all the kit in the world won't matter if you can't evac the real emergency
Second do you know the allergies and medical conditions of those you travel with? Are you making sure they have their regular meds?
I do chest compression/bagging/shocking people in a big ol' hospital and it doesn't come out well often, in the field I have seriously thought about getting an AED since prices have dropped so much....but while I carry a face shield I know that unless EMS is coming fast that field CPR is something you are doing for the sake of everyone watching.
Now to the med kit
Rolled gauze, lots of rolled gauze......none of that silly paper packet crap. Rolls are cheaper, you cut off what you need or stuff the whole roll in.
Water clean enough to drink, lots and lots of water to wash wounds. People too often dress and forget. The more remote you are the more frequent dressing changes and wound cleaning (pain is good as it is still living tissue, worry when numb)
Direct pressure is the best way to stop even major bleeds....yeah having one of those cool tourniquets is a good idea, but for ONLY when someone or yourself can NOT apply direct pressure till at a hospital/ambo/copter
Quality tweezers like ladies use to pluck hairs
1 pair hemostats
Cloth medical tape 1 in wide
Coban style "tape" wrap
Ace wrap
NEVER carry sutures unless you are 1) going to a 3rd world country and will hand them to a medical professional 2) yeah no see number 1
If you disagree then explain to me that you are a medical professional, trained to suture and do it alot, will deal with the pocket wound, can sew on yourself or someone screaming in your ear, are willing to take on the liability and blah blah blah......sutures are the dumbest thing I see in kits.
Look up Woundclot, best stuff I have seen for bleeding control and I am trying to get it into our hospital, stuff is amazing and cheap enough I use it around the house.
Nasal airway, not hard to put in and won't cause gag like an oral, and sorry dude above but I work Surgical Recovery alot and deal with airways all the time, I do chin lifts, jaw thrust and there are plenty of times you HAVE to place a trumpet. Carry a couple of sizes as the weigh nothing.
Now for meds..... #1 thing is if you keep them in your hot car toss each year on your birthday
Forget all those cute single packets, go to your bathroom and pull from the stash, get some small containers and cotton balls.
Benadryl pills & cream, lots of pills as 1 dose usually isn't enough
Tylenol 20 tabs of 500mg (or bring a small bottle if space)
Ibuprofen 20 tabs of 200mg (or bring a small bottle if space)
Aspirin (be careful about bleeders) (5-10 tabs....this is more for chest pain use above for muscle, joint, cut pain)
Tums/Pepto tabs
Never Never Never use those pills that stops diarrhea, pooping your pants is better than trapping the bad stuff inside your body.
Some dry electrolyte powder just in case someone is pooping/throwing up and you need to replace what they are loosing. If they are bleeding just keep giving enough water that they are getting mad at you. They will complain they aren't that thirsty but it is really really hard to replace blood with oral at the same rate.
So here is what you will really deal with
insect sting
Tummy ache (didn't wash your hands enough when prepping food or eating jerky while driving down the trail)
Cut your finger slicing limes for drinks
Cut your hand/arm during trail repair
Burned your hand/arm making smores
Scrape your knee hiking for firewood
Twist your ankle getting that selfie
Fell and sprained your wrist limping from that selfie
Hit your leg with the hatchet/axe while cutting firewood (evac)
Smashed your hand/foot working on your rig (evac)
Chest Pain (evac)
Severe Asthma (evac)
Stroke (evac)
Think through everything you have ever been through or seen and add a few worst cases and you will be fine.
Adventure Medical Kits has some of the best setups and they sell refills
Get "Where there is no Doctor" or the Wilderness Medical Inst book or a few other good books for your kit....I can post pics since I own pretty much all of them for this type of discussion.
SAM splits and collars are cute and fun but you can do the same thing with stuff in your truck....remember much of that was designed for backpacking not when we have 2 tons of truck with us.
Ok rant off for now as I could spend hours on this topic.