It's worth noting player distribution, Masamune shares a data center with Chocobo and Shinryu, the two most populated JP worlds. And though Tonberry is very populated, it's mostly on a center with fairly low pop worlds. (Even then, Chocobo only has about 12k active players, compared to Balmung's 18k and Gilgamesh's 15k! And those numbers are from before SB's release)