Do Buddha represent the Cosmic Man? Does it have similarity to Brahman?

Why the historic saviours and prophets of mankind only existed in scriptures or only in the past? Why do no saviour was found in the world, which have seen by some men actually? Why Buddha keeps his hair, but the disciples are bald? I believe the Buddha is synonym to the cosmic man, the Brahman or the Absolute of the Upanishad. I feel no man named Buddha existed but the term coined to the awakened one or the absolute. It has been replaced with Brahman. Shaven head of disciple means they have shaven their mind of impurity to attain the Teacher, The Tathagata. The 'Tat' is Upanishadic word from greatest dictum, 'Tat Tvam Assi'! Do Tathagata really mean who have arrived at 'Tat' or the Absolute? Please I have these doubts in my mind!