According to Jiraiya,the Sage was a monk who appeared long ago in an age of endless war. He was the first to discover the truth of chakra,and with it he tried to lead the world to an era of peace instead of conflict. He travelled across the land, spreading his ideal and religion, the Shinobi Sect which eventually came to be known as ninjutsu. His great deeds and ultimate desire to bring peace to the war-torn world made him widely known as the Saviour of this World Centuries ago, the sage defeated the most powerful demon in the ninja world the Ten-Tails and was praised as a god for the virtue of his victory.
Now then how could a man have followers and even a story if he fought the juubi a near decade later?
And to you all if both of them had a different eye why doesn't rikudou have tomoes?