A lot of complaint I hear are about the 1 unit per tile limit, and the fact that it often lead to bottleneck and traffic jams. Issue is, traffic jams are pretty much a basis of any large scale warfare. In real life, commanders often cursed about the supply train of X division was jammed in the rear, preventing Y division to go foward. They had to go around. Traffic jams are impossible to avoid by design, but they are quite easy to mitigate, for instance by planning in advance your road system (note : which was pretty much what European powers did in the 19th century) : a railroad connecting all border citites with an handful of ''tendril'' roads leading to the front (and that will be removed eventually) allow for pretty fast redployement of units on other fronts. Of course, on offense the one unit per turn often leads to huge bottlenecks-that can be mitigated pretty easily if you build roads as you advance, even if you need to remove them after.