Unrealistic? The river gets deeper and more unaccessible up and downstream, the nearest bridge is miles away, so the bridges are a crucial site to dominate, two local lordlings know that and release their armies.
About the layout? One side is a plain with a forest, good for cav and anticav, the field is similar (fences instead of trees), the main ruins (no doubt result of a previous conflict for this piece of land) offer cover and fun fights. The stone bridge is a very good place to make a last stand.
Water? Well, you got a river! If you dont want water, go to the remaining 85% of the map (estimate).
What else do you want in a map? I really like it