I mean, there is some leniency with weapons in this setting since, for one, the people wielding them are generally superhuman (a lot of the weapons from the game are certainly not exactly suited for use by normal humans - can you imagine trying to swing a kirkhammer in real life?) and that magic-not-called-magic is a thing to an extent, but I'd prefer if there was some measure of logic to the weapons.
As I said, a giant stake-launcher might actually have a practical application... though I wonder if anyone would dedicate the resources to design and make the weapon given how narrow the possible uses are.

(I also privately wonder whether naming it "Vlad" would make sense in context. It makes sense to us because of Vlad the Impaler, but I don't remember Bloodborne even once making reference to any kind of myth or historical events/figures (or country, or much of anything, really) that would have come from our Earth aside from using our languages.)