According to Osho, all buddhas share one taste of truth; thus any buddha can speak for all. Apparent differences come from our conditioned interpretations, changing languages, and differing audiences that required varied methods and emphases. At the level of silence there is no disagreement—only in techniques. Don’t idolize non-difference either; drop the mind and see.
Deep down, all enlightened ones mean the same thing; we just hear it differently, so they teach in different ways for different people.