I actually played the same scenario yesterday(Total victory btw ) And when I saw those reinforcements I knew that it would be pain in the ass to get them to front. But lucky me the enemy took a longer route so I just selected all halftracks and gave them a "quick" order to a field near the town. Sure it took some time to get there, but I actually didnt even need those troops. But yeah that same problem has been around since first CM.