Yamanaka and its not even close more skilled and more proven than the other two and would be a huge favorite to beat Kameda and Payano.
I had long felt Anselmo Moreno was the best bantam and was for several years. But Payano did a number on him in their abbreviated fight and now more than ever there can be no argument made for anyone other than Yamanaka, really. Big fan of Tomoki and obviously in besting Moreno, Payano has my interests as well.
The other threads, I expect people to not be able to control their bias and agendas. As much as I like all three of the Kameda brothers, I find it amazingly puzzling that anyone could honestly fancy him a better Bantamweight than Yamanaka. Watch Yamanaka fights, people. He's one of the better titlists in boxing.
Cabellero should be included, but I don't know if McDonnell holds a regular WBA title. Either way, they'd both be behind Yamanaka by some margin (even though I like both fighters quite a bit).