Was Lwanda Magere a real historical figure or purely mythological?

I've been researching the Lwanda Magere legend and I'm struck by how detailed and specific the stories are — the location of the stone, the Nandi connection, the shadow weakness. Some oral historians argue there was a real warrior whose exploits were amplified into legend over time. The stone near Sidindi is a real geological formation that predates the legend. What do others think — historical kernel or pure mythology?