Yes, one knife probably CAN do it all, but was that the custom?
In Sons of a Trackless Forest, Baker notes that the "large butcher knives" were sold at £7.6.0. That's a pretty hefty sum, btw with the monthly wage for the hunters being on average about £4. There are some hunters shown in the ledgers of the trading post as having purchased such an expensive knife. There are others, however who bought knives for the cost of 5 shillings, including several entries where the individual bought two knives at the same time. These are the most popular knives as far as sales on concerned, but is that because they wear out quickly, are used in trade, or are the owners carrying more than one knife for different jobs, upon their person? Who knows?
The cost for a "butcher knife" (in contrast to a large, butcher knife) was £3.10.0.
There is a mention of a "cutteau knife" that appears to have cost a mere 3 shillings.
A razor cost 3 shillings, which are sold at least twice in the ledgers, but the question then is for shaving or some other cutting purpose?
I have found that a very large butcher knife, while probably a very good item in a hand-to-hand fight, is not so good for dressing, skinning, and butchering deer. I confess, that I am not dealing with animals the size of elk, and the bison are centuries gone from the East, so..., I might find a different result were I harvesting such large animals.
I have found that a 6" blade (which I wear on my hip) is quite sufficient for all of my camp chores, including butchering up a harvested deer. A small 3" knife works very well for dressing that deer, as it's a lot easier for me to wield that sharp little knife, "blind", inside the deer cavity when severing the internal connections for the organs at the throat, as well as for skinning that deer. Plus that little knife is good for cutting patches or for a very quick and crude knapping of the edge of my flint. So I carry two at hand, plus I carry an additional 3" knife in the pack, in case I lose the one I normally carry. Now at a historic site, when I am playing a person who might have to venture out to areas where I might meet an adversary while unloaded or while loading my rifle after dispatching one of a group of adversaries, I carry a very large knife. It's mostly for show though. So in that case I have three at hand, instead of my normal two.
LD