In shooting bags a pocket or two inside or on the outside is a good idea for small things needed quickly e.g. flints, flint leather, knapping tool. Patches and balls should be in large enough containers that they should stay at the top if shooting frequently. It really depends a lot on what you carry with you. As for a haversack, remember that it is intended for the carrying of issued food. However, that being said, I have the following description of a haversack written by an officer in the British Army fighting in Spain and Portugal against the French.
"The mess have a good many things in common, but the contents of the haversack are exclusively
the property of its owner; and a well regulated one ought never to be without the following furniture,
unless when the perishable part is consumed in consequence of every other means of supply having failed, viz. a couple of biscuit, a sausage, a little tea and sugar, a knife, fork, and spoon, a tin cup, (which answers to the names of tea-cup, soup-plate, wine-glass, and tumbler, a pair of socks, a piece of soap, a
tooth-brush, towel, and comb, and half a dozen cigars."
All this being said, I am currently making a new one for myself that experience has shown seriously needs a pocket to keep small things from the bottom of the bag as you said.