How you pack your gear is a very individual choice. For example, my SAR buddy Scott has this giant backpack with everything he owns in it, no outside pockets. When we get called to an incident, he digs in there and tosses out all the stuff he doesn't think he'll need, and then he's ready to go.
My approach is different. I've got a small pack that holds my "always take" gear (with all kinds of crap hanging off it - I look like a garage sale going down the trail), and then a duffle bag full of other bags with more food, more shelter, more tech gear, more medical supplies, etc. While he's throwing stuff out, I'm throwing in what I think I'll need more of.
What really matters is to have what you need when you need it, and there are many ways to get you there.
Parker, who never even considered the idea of an "urban" pack...