The texture is not terribly strong, and the cities are reasonably well spaced out. Have you considered going without banners and just making the labels about the size that they would have been if they were on the banners? You might need a little bit of padding around them if they crossed a border line, especially where they cross coastlines. Your city density is roughly similar to that of Ticket to Ride: Europe, so a label size similar to that board would probably work out well for you.