"He obviously wasn't talking about literal swords, since he rebuked Peter for cutting the guy's ear off with one in the garden, and he then healed the ear. The swords were metaphorical."

I am not so sure. Maybe he was just so digusted at Peter's incompetence with the sword. If I tell you to arm yourself for conflict, and you use that arm inappropriately, does that mean I did not tell you to arm yourself?

The swords were real. The statement is a statement of what Jesus wanted his followers to do.