You're totally right about that river splitting off kind of randomly. Not sure why I didn't notice that but I suppose that's what these threads are for!
Also a good point about coastal erosion eating away at a delta like that because the Mississippi is one river I looked at quite extensively in my reference work but I was unaware of how extensively that delta was maintained.

Made some changes. Most notably I got rid of the two rivers that randomly split off and added a secondary lake connected to the first one to make sure there'd still be plenty of water supplied to that part of the peninsula through this system to support the marshy conditions.

Map_Cassonia-Latan_02.png

Thanks for the feedback!
And yes, Bruges is a beautiful place to live. Glad to see it's known all the way across the pond.