Black Horses for the King (1996) by Anne McCaffrey is a divergence from her usual fantasy and SF fare. In this historical fiction, aimed at young adults, a boy helps King Arthur buy horses, and in doing so, helps him to create the cavalry of Camelot.
The story is first person and mostly straight forward. There isn't much cleverness going on, but there doesn't need to be. The tale itself is experiential, at that cusp where a boy turns into a man, and where his fortunes change from subordinate to peer.
The text moves well. The plot progresses steadily. The characters all seem a little underserved, but there no harm of the story. The antagonist is an annoyance, more unbelievably so than he ought to be, which really weakens his role. The history and horse facts are generally correct with some liberties taken to create a good story.
Overall, I found the work a competent read of YA fiction, perfect for the boys, and possibly perfect for horse girls.