“Bar kochba definitely wasn’t annointed- there was no Sanhedrin then. But the Rambam calls him king, and candidate for Moshiach so you clearly see what kind of “king” the Rambam was referring to.“
Correction, bar Kochba minted coins during his lifetime so they can be used (like the United States government) whereas the Rebbe has not (not even his “Rebbe dollars” were minted by him)