The tin feels a lot better, I'm still having lots of issues with traders though. They'll wander off somewhere random and just go in circles or they'll walk right up to their destination and stop all in a pile having not even dropped off their deliveries. My sea routes and land routes are marked as such. The circles walking seems to be mostly an issue for cities with both land and sea trade routes. The guys that just stop in front of their destination seem to be mostly an issue for trade routes that cross multiple regions.