Hi, Gibb. *If* the 7th Cav. Tompkins was the one intended, the stanza was likely spread by officers, presumably some of his personal acquaintances.

The social distance between officers and enlisted men in the "Old Army" was vast. They were forbidden to socialize.

As Wiki-P suggests, Col. Tompkins wasn't much of a figure. All we're told of his career before 1915 is that he "participated in the Battle of Wounded Knee" in 1890. The article on Wounded Knee calls Tompkins a second lieutenant at the time.

I suspect that any "Tompkins" was likely to be nicknamed "Tommy."