Just my 2 cents -- From past experiences fixing broken people, I've found the items most useful to me have been (in no particular order):
Something to write with and write on, perhaps with a pre-filled soap-style note scribbled on there.
A bunch of glove pairs to give to people to assist with patient assessment, and for when you need to get stuff out of your bag after your first pair is covered in blood. Also, if you have multiple patients, you have to protect them from each other, which is extremely hard to do well.
Large amounts of gauze to mop up blood/stop bleeding so you can see what's going on. You don't want to give away your gear to do this.
Something super light to splint with. There seems to always be at least an arm fracture or tib/fib involved in alpine falls involving crampons, etc. I'm back to carrying a sam splint in the foam frame of my pack as I don't like to give away parts of my gear to people.
3 cravats and safety pins, kling, tape, and ibuprofen (offering it to let them self-administrate).
Something for the patient to sit/lie on if possible. They're often lying in snow for a really long time. Almost every single patient has been hypothermic to some degree. Again I scour the patient's pack for something before I give away anything. Usually just dump all their stuff out to see what you have to work with.
WFR's pretty much the most you need when you're not expecting to be dealing with a patient, but it is damn nice for the patient to have the emt-p to administer morphine, IVs, etc. That stuff's just not around until later though. I'd rather have an _experienced_ wfr over an emt-b along if I had to choose.