It could be fine, if player (AI alsou) could build routes for speeder traveling. Route between two baronies could decrease time in half, cost could depends on terrain boath baronies. Route could also influence the speed of gathering of army. The system already calculates routes for traveling each person, so main work is on the visualization on the main map. If this could be problem, map for traveling should be OK. Route is not necessary for playing, so the cost could be relatively high, because influence is big. I hope. that this will be nice mechanic with potencial trade routes (silk route) and merchant republic.