My issue with merchants is that I have to keep track of where I have sent them. For example, a merchant is created, I sent it off to Edo. Before it arrives, another merchant is created. Since I have yet to actually form the route with Edo, Edo is still on the list of potential targets. I have to remember that one is already en route to Edo and choose another target. A system like Civ 6 where you choose the target settlement and commit to it would be welcome.