I tend to think in layers, with redundancy built in.
Worst case, I go with what is in my pockets. Knife, lighter, small flashlight, and whatever else I happen to be carrying.
I have a small pouch with a basic PSK in it, augmented by flashlight, AMK blanket, pocketknife, lighter, etc. If I grab nothing else, this goes with me. The primary grab it and go pouch if you will.
Next up is a vest with some of the same items, but including water bottles and some food. The pockets spread the load and there is room to add items as I come across them.
Finally there is the pack with "comfort" items such as food, cook kit, stove, more water bottles, poncho liner, clothing. This resides in the same closet as my gun safe. If I have time to grab it, then some of the weapons go with also.
I tend to keep these items slightly separated but readily accessible - the exception being the weapons are under lock and key. I can grab what I want/need/desire quickly should the conditons warrant and beat feet. Should it be a bugout in place, I still have the gear ready to be used.
I'm thinking along the same lines. The EDC, then the pouch, then the butt pack (or in your case, the vest), the 3100ci SHTF bag. If the big one stays in the vehicle I'm traveling in or next to the door when I'm home, then I can always choose to take the butt pack to where I need it, or even just the pouch.