Definitely it's a coincidence. You can find much similar images. Often this kind of illustrations (composition and poses) are used at posters and book illustrations.

Also this moment from my illustration was in the original movie Lord of the rings - Brotherhood of the ring. There was a moment when hobbits hit under roots of tree and the Nazgul climbed off the horse and came close to them. I took this scene and removed all unnecessary. Then I mixed one more moment from that film when the Nazgul attacked hobbits in ruins.

It's all, and I didn't see your illustration before.