When I do these small kits, I think "what would kill me the fastest if I were lost stranded in the woods" and what I come up with are these:
1. exposure
2. dehydration
3. traumatic injury
given that what I focus on are fire/shelter and water. I then try to add a couple of things to make life a little easier/assist me in making fire/shelter and water. For the traumatic injury I don't think you can put a very useful trauma kit into an altoids tin. So here's what I have in my kit.
storm proof matches in small plastic bag, small bic lighter, jute twine soaked in melted gulf wax, small folding knife, two band-aids, two 12 oz gerber breast mild resealable bags, four katadyn water purification tablets, two antacid tablets (for my heartburn) and two benadryl tablets (in case someone I'm with has severe allergic reaction to insect bite), streamlite nano light. I then use thin gorilla tape, about 2 feet, to tape the tin closed around the edge. Then I use two ranger bands to secure a packaged emergency blanket to the tin. This, however, will not fit into the esee pouch. You might see if you can somehow secure the e-blanket or a contractor bag and some cordage to the sheath elsewhere.
For me, I want to address the most dangerous environmental concerns immediately. My personal opinion is that fish hooks or snares just aren't going to help me survive a freezing, wet, couple of nights out in the bush and that I'd be better served with making damn sure I've got something to warm myself with and to get some water to drink. I do have the band-aids and duct-tape in there t take care of annoying, minor injuries that might hamper my shelter building or whatever. YMMV, Good luck!