You claimed that rapiers were not suitable for warfare. Demonstrably false.
Then demonstrate it. You claimed they were used in battle all the time, and then for your example gave a musket unit from near the end of the rapier's life. I didn't make you say any of that.
You claimed that they didn’t exist in the 15th century. Demonstrably false.
If by demonstrably false, you mean, definitely true. Look, we're all trying to have a good time here. If this isn't fun for you, you can always go poke around in someone else's thread. I've already put my sources on the table, and I don't particularly feel like repeating myself. I just don't find what you had to say convincing. At some point, you are going to have to accept that and move on, or bring something more persuasive to the table.
I'm not even sure what you're trying to prove, other than the (easily verifiable) incorrect claim that rapiers are a hundred year older than they were, or trying to claim rapier fencing existed to any extent in Renaissance Germany, which for practical purposes it did not. If you feel so strongly, maybe you should head over to
Wikipedia, where the article on rapiers says they were invented around 1540, and try your evidence out on those guys.
So, yeah, I'm going to keep directing the conversation back to the peculiar event that, probably in D&D third edition, the rapier was added to the standard weapon list, and given fairly optimal stats for a Dexterity-based wielder, making it a standard option for certain kinds of characters. The implied use, then, being that dungeoneers would be carrying a civilian dueling weapon into the dungeon, instead of contemporaneous sideswords, cutlasses, axes, and so forth.
I'm pretty sure the rapier first appears in A Mighty Fortress, but maybe I missed a source upstream. Is anyone aware of an earlier appearance? Its presence makes sense in an Age of Sail game, but it feels incongruous next to a weapon list thoroughly culled from a 12th through 15th century armoury, plus a couple of historical odd bits like the kopesh.