I just finished taking a 16-hour Wilderness First Aid class so have fresh information.
Small gaping wounds (like an inch or two long) can be thoroughly--extremely thoroughly!--irrigated with an irrigation syringe (using treated water) and closed with sterile strips. Put a thin layer of antibiotic ointment over it and a transparent bandage (Tegaderm or similar) so you can see if the wound is getting infected without having to remove the bandage. You usually can continue the trip. Check several times daily for signs of redness--if any, it's time to bail out.
Large gaping wounds can't be cleaned thoroughly enough to risk closing without serious infection. Irrigate as much as you can and just pad over the wound; don't try to close it. Definitely do not suture--the first thing that will probably happen in the ER is that the doc will remove the sutures and give you a severe lecture (if the doc is my son-in-law, he most certainly will!) Obviously someone with a wound of this type needs to bail out on the trip, although they can usually walk unless there has been a lot of blood loss.
The same is true of puncture wounds--irrigate and cover and get yourself out to medical attention. Such wounds are about 100% sure to become infected. If it becomes infected, it will take far longer to heal, and you're risking a generalized infection.
Abrasions (i.e. skinned knees and elbows), a more common injury, may have to be scrubbed thoroughly to remove imbedded dirt despite the pain. Scrub, irrigate, scrub some more. If not too painful, trip can be continued, but monitor closely for infection.
Wounds with severe bleeding, once you've stopped the bleeding, obviously need to be evacuated. If the patient (they're not "victims" any more, it seems!) hasn't lost very much blood, they may be able to walk out with assistance. If there is severe blood loss and shock, though, it's time for SAR and a helicopter.
Also, stuff like alcohol, iodine, betadine (a form of iodine), hydrogen peroxide, etc. that once upon a time was used on cuts and scrapes should be used only on the skin around the wound, not on the wound itself. It damages raw tissue and retards healing. The same is true of antibiotic ointment--don't put it down in a gaping wound.
The first aid kit you take for yourself will probably be pretty small. I've never had any injuries in the back country except small cuts/scratches on my hands (to which I'm prone), an occasional blister or mildly skinned knee or elbow. My personal first-aid kit therefore consists mostly of bandaids (mostly the water block type), a couple of elbow/knee bandaids, antibiotic ointment, a little moleskin and the inevitable duct tape. Additional items I take are a couple of Tegaderm pads, a couple of sterile gauze pads, an irrigation syringe, small tweezers, a tiny mirror, foam self-adhering wrap--called veterinary wrap in a farm store (where it's lots cheaper!) and "first aid tape" by REI (lighter substitute for elastic bandage), tylenol (for headache & fever), ibuprofen (for muscle and joint aches), buffered aspirin (for my dog), benadryl and lotromin. Everything but the tylenol and ibuprofen (poisonous to dogs) will work on either me or my dog. For the dog only, his pack contains an extra, too large bootie in case of cuts on his pads.
For a group, there should be a group kit which would contain more. One irrigation syringe per party (as long as everyone knows where it is!) would be sufficient. You could even take a SAM splint for a large group.
It's a good idea to go through the first-aid stuff at least yearly to replace expired meds and bandaids whose wrappers have turned yellow and the foam self-adhering vet wrap, which, I found, after a couple of years will have fused together to the point that it's useless.