The Lord are same but the philosophy is different according to the time , place and Circumstance
There is an article on which says: "Buddha is also an incarnation of Lord. But such incarnations are not considered to be very advanced in Vedic knowledge(Lord does His own ways). There was a special purpose of Buddha incarnation. So called Brahmans of that time were slaughtering animals on the names of sacrifices given in the Vedas. So Lord incarnated to take away people by preaching Non-violence."