Actually, Yukinose backed down on Buri because he was too low-tier, and moved on to a top-tier(Testament).
In Slash, Ogawa backed down on Eddie(for a while), and moved on to Ky because he was top-tier, however he later did move back to Eddie and continued to own just as much. But, the fact that he moved to Ky still stands.
This shit happens all the time with top players in japan, so yeah, the japanese tier whore as much as the US does, if not more.