I loved this book and so did my son. Not sure I know the answer to your question, but I can see where it is an Adventure. It doesn't read like a typical "Historical Fiction" for one thing, at least not to me.

My son and I were glued to this book as we read each new adventure the boy Agba and his horse took. Their travels, hardships and triumphs. I was so into the book that I even cried as I read the last portion of Chpt.22, when Agba sees his promise to his horse fullfilled, "...I will be a father to you, Sham, and when I am grown I will ride you before the multitudes. And they will bow before you, and you will be King of the Wind. I promise it." He recalls this promise as he was riding his horse before the multitude, after everyone saw the true value of Sham. The book to me is about the adventures they took together to rise above their circumstances. I've never gotten so into a book like I did this one.
God bless,
Tre