Interesting, I didn’t know that bit of history. Around here, a pasture is generally a wide open space, used either for cattle grazing, or growing feed, or hay, and a cowpen is a smaller fenced area used for separating cattle or feeding. Usually knee-deep in manure and mud this time of year. I’ll give ‘em a pass for naming their ship that then..LOL.
Yes, well, they were public lands then, or no-man’s lands, so anyone could move their animals there and use it a while or while they moved cattle. Just loose usage of words, that’s all.
As for the name, yes it is funny on the face of it. Unless you view it as a threat - you are the cows and we’re going to pen you!