Krishna isn't a person, and because of all the lineages, there are many who are important, but no individuals that stand totally alone. None would ever have the audacity to claim they were greater than God.
The information provided in the Hindupedia strongly suggests Krishna was considered a real person.
Here is what Swami Tadgatananda says about Krishna:
"Devaki's child was but the plenitude of
Brahman,
pūrna brahma, manifesting its powers through the human form of an
avatara, to uphold
dharma and restore balance in
a world afflicted with anomie. He was quick to remind his imprisoned parents about his true nature, and the parents, gifted with divine insight, were equally quick to apprehend the implications. Mother Devaki could not hide her awe:
That you the Supreme Being, who hold the whole universe within yourself at the time of your cosmic sleep, have been born of my womb is only your imitation of human ways to hide your identity—what a great joke you are playing on the world! Bhagavata
Krishna was not the first incarnation of
Vishnu. So Devaki was not unaware of the special manifestation of the Divine
in human form. But to have the Divine for one’s child was overwhelming even for Devaki. The incarnation is ‘the meeting point of all contradictions, the best visible expression of the invisible divine ground’, and in Krishna, the eighth major avatara of Vishnu, we find reconciled a host of paradoxes. That the
apparently frail infant in Devaki’s lap could inform her of his extraordinary nature was only one of the
many acts that sets apart Krishna from other humans, even as it points to the infinite potential latent in the human frame. Of the many avataras—and the Bhagavata speaks of the possibility of infinite divine incarnations-
Krishna’s life remains uniquely etched in people's consciousness. Not only have
his life and teachings had a major impact in the development of culture both religious and secular on the Indian sub-continent; his legend has been an integral part of the lives of numerous people down the ages.
His miraculous and heroic exploits have provided the theme for numerous and varied representations in literature, art,
music,
sculpture, folk song, and drama. For littérateurs, artists, and spiritual seekers he is an eternal inspiration. "
By Swami Tadgatananda
Krishna - Hindupedia, the Hindu Encyclopedia