That looks lovely!
And honestly, I think the variations in the olive tress give the map a lot of life. It makes it more dynamic than it would be if everything was exactly the same. I really like the olive branches the way they are. I do see what you mean with the sea strokes, but maybe here you can even it out a bit with careful use of colour? I don't know in which direction you want to go with this, but I think it's a great foundation for a lovely map and I'm excited to see what you will do with it!