> Sheaths also sheath swords.

So? Sharing an extremely general trait with many things including swords isn't an analogy to swords. Is wine analogized to aggression because guns have barrels?

Besides scabbards, the other prominent use of vagina in Latin was to refer to the husk of grain. Do you conclude that an analogy is being drawn between sex and nourishment? Sex and worthlessness?

Wouldn't that conflict with the idea that the use of the word vagina is an analogy to aggression? How can the same fact be evidence both for and against that idea?

> Relatedly, the slang (or 'real') word for penis is/was weapon in old English.

Why do you think this is related?