I'd say it is a quite decent start. Yes, rivers could be curvier, but they aren't doing anything unnatural. This could easily represent the geographical knowledge of someone in the setting, without an extensive survey or satellite photos to location every bend in the river. What I don't like is that some river names run top-to-bottom, while others run bottom-to-top, while the rivers would all be flowing the same way, so it isn't some clever follow-the-flow variation. If I were actually going to use this map, the thing I'd most want is indications where roads cross rivers as to whether that is a ford or a bridge (or maybe a ferry) at the crossing.