The BCB wire saw goes into my Altoids tin. The SAK with saw a pocket and bowsaw and Hudson's Bay axe the slots on my german rucksack. It's called layering people, just like clothing or firemaking redundancy. Once in awhile that wire saw is actually handier for some cuts.
And more often than not, it's like all the cutlery and firearms backing each other up and never used.
Unless you are in a survival situation, or what could quickly TURN INTO ONE, please think woodsmanship first.
Choose your trees with the eye of a tree trimmer or forester and leave the forest a little healthier.
Again, I recommend the crosscut saw manual from the website I listed above. If you understand the very sophisticated technology of a quality handsaw the optimal use of everything else is better understood.