One pound makes 4 pairs

I'm working on Civil War "Socks for the Soldiers...or Army". There are many printed versions for these socks or stockings. At times the same directions were printed in newspapers, both the north and south. One common feature was that one pound of wool yarn will knit up 4 pairs of socks. But, and there are always buts in historical knitting, some directions state to knit plain heels and toes, or knit the heels double and plain toes, or knit the heels and toes double. There are a number of ways to knit double heels.

The current directions I'm working on state "One pound of yarn, costing from seventy-five cents to one dollar, will furnish four pairs of socks. The heels and toes should be knit of double yarn."

So...I'm questioning...if one pair of socks uses 1/4 lb or 4 oz of wool does this factor in the extra yarn needed to knit the heels and toes double, when other directions leave that specific part out? There are also articles specifically about heels which state to knit the heels double. Makes one wonder who developed the original directions, what was written and what was added later to make a better sock or what was left out for editorials sake to make the directions short and sweet.

There are many variables to consider then and now. Based on the printed directions, I expect the yarn used was commercially spun, but not every one purchased the same wool yarn, or they used homespun. Did every one spin the exact same weight? Is all the wool from one type of sheep? We know mixed wools were spun to enhance certain attributes of a better or worse quality wool, etc. Plus directions call for "large needles and coarse yarn" Then you also have to consider the knitter, loose, even, or tight. A lot of variables.

This can get complicated...but if I don't ask these questions...am I doing good research?