> as I believe may have been the case with "Shenandoah"

And a basilectal form of some other word might have resulted in both "maringo" and "my kingdom."

Don't know what, though. Just sayin'. ("Mandingo," no way!)

Am intrigued by your ref to "Shenandoah." There's that one text that got transcribed as "Oceanida." But you seem to have something else in mind.