Referring to the White Tool Catalog, the adzes with the pin polls are ship and bridge carpenters tools. My guess for usage of the poll relates to bedding, decking and planking operations especially rehabs where old nail remnants are likely.
http://toolemera.com/catpdf/lijwhite1905Cat.pdfThe swing for striking, for the purpose of punching in a nail would be short and measured, in contrast driving railroad spikes with a full round swing. John Henry was not only a man but an artist of industry. Hitting the target should not be a problem.
Anyhow, this is speculation, give it the weight it deserves.
