They already said that "if" they do Dark Knight, it would be based off of Gladiator. This goes back to the concept of light/dark Pld/Drk, like we saw with Cecil. Drk, if it does get added to the game, will likely require Glad30/Thm15 on principle, just like how Pld requires /cnj15 on principle.

They cannot deny that these new weapons are based on the mythic weapons of Final Fantasy XI - Not only are the names of 5 other jobs the same as their FFXI versions, but they're no doubt going to be involved with that "Alchemist from the Far East, Jalzahan." That name is too odd to be a coincidence, and SE loves connecting things - Jalzahn was a former emperor of Aht Urghan.

As for why Brd/Smn/Sch names don't match:
Brd had a dagger, Ranger had a Xbow - no mythic longbow.
Smn & Sch - they use books in XIV, not staves like XI. If they used staves, they would've been named Nirvana & Tupsimati respectively.

It's a MISTAKE on SE's part to call it Liberator when it SHOULD be Ryunohige.