Carry the extra balls and patches in a leather ball bag. That fits most any space. I put the tools in the bottom of the bag, and don't worry about them. I can always reach them if they are needed. I did carry my jags- ball puller, and patch puller in a pocket on the inside of my bag for awhile, but decided that the bottom of the bag made more sense, and use the pocket to carry cleaning patches, now.
Consider making a loading ball block, where you put your needed extra patched round ball, already lubricated, in the blocks. Depending on how long or large you make the blocks, you can carry from 3-10 extra balls, ready to load. I prefer carrying several small blocks, so I can leave most of them at my car, or in the range box, if they aren't needed. I load from my range box, rather than from the pouch at the range. I only use the bag when hunting, or doing a hunter's walk. On a hunter's walk, it makes sense to use the loading blocks- multiples, to carry whatever the course requires- rather then tote along all the loading and cleaning components in your bag.
Oh, my nipple wrench stays in my range box in my car, or at the loading bench, rather than taking a hike through the woods with me. I have only once needed the wrench, and that was during a parade my club was marching in. My box was in the back of our covered wagon, where I obtained the wrench, to remove another member's nipple to clear it, and to clean the flash channel underneath it. We did this while walking in the parade, and we got his gun back into shooting condition. We were shooting off blank charges of powder to scare the Cicadas, and irritate the Anti-gunners. We had a very good time, and the number of people along the parade route who applauded us when we fired the guns far exceeded the number who gave us dirty looks.
You too will find, in time, that you are trying to carry too much stuff, and that there are better ways to carry things than those large tins. ( I use smaller, 2.5" diameter brass " tins" sold by Tedd Cash Products for my precut patches, and cleaning patches. They provide more than enough patches for my use in the woods, with no threat of running out.)
I have a ball bag, and I carry the lead balls, and the precut patches in that bag. I use spit as a lube on hunter's walks, so the patches don't foul the inside of that bag. You can buy the ball bag from many suppliers, including Dixie, and track. You probably can buy loading blocks from them, too, for that matter. Its more fun to make your own, tho'. The drill sizes for each caliber is listed on the Index page, under Member Resources, and " Charts".
When I am shooting percussion, the two biggest items I carry in the bag are my short starter, and a pair of needle nose pliers. I could buy a smaller pair of pliers, but I have several of the standard size given to me by my father,and I just can't see any reason to spend the money for something smaller.
I keep promising myself that I will sew in a loop to hold both the short starter, and the pliers, but I have not gotten around to it. They just don't get in the way enough to motivate me to do that work. Its your bag. Shape it for the way you want to use it best.