I question your identification of Buddhism with Legalism. Your argument presupposes a triad of Daoism, Confucianism, and Legalism as the three primal orientations in China, with Buddhism siding with Legalism because of its opposition to both Confucianism and Daoism. This does not follow. It may well have been true during a particular historical period, however. Can you name one where Buddhists clearly supported Legalist positions rather than merely opposing Confucianist and Daoist ones?
I note that in the medieval period the neo-Confucianists suppressed both the Daoists and the Buddhists and arguably adopted some Legalist attitudes themselves. Barkley Rosser
-- Rosser Jr, John Barkley rosserjb at jmu.edu