I'm not sure R/H would have worked out long-term, but H/Hr makes even less sense, as they never displayed the barest hint of attraction to each other despite being hormone-riddled teens. Harry's relationship with Hermione always reminded me of me and my brother - different approaches and driving each other up the wall sometimes, but still sharing a deep familial love that will always be a constant in your life.

In my opinion, all the trio's relationships with each other were much more meaningful as friendships anyway.