I know Paradox is keeping Eastern Buddhism as just a stand-in name but they also make it difficult as they aren’t accepting of new religious names such as sanjiao or three teachings because it’s too sino-centric yet have Vietnam and Korea keep that religion instead of splitting it while Japan get its own unique religion.

How about Heaven Worship? Pretty sure everyone in these countries all worship 天 at that point of time regardless you’re buddhist, taoist, confucian, animist, shamanist, folk religion.