This system is stupid. At least insofar as its current implementation, it is really, really stupid. I get that people think it makes the warfare in Civ more "tactical" or whatever. But if the devs aren't capable of bringing on really smart people to program really smart AI who know how to wage tactical warfare, it's a bit lousy, isn't it? But the worst thing is how it turns the whole game into a traffic jam. City states build a dozen warriors and spearmen and march them all over god's green earth for the full length of the game. They stand on the roads. They block the roads. I cannot build more roads, because the devs still think it's a clever idea to sacrifice gameplay for the sake of some historic parallelism between roads and trade routes. Then if I want to send a missionary down that road, it gets blocked by the city state's stupid warrior, who is just standing there doing F A. Why? It doesn't even make any freaking sense. Why would a non-combat unit compete for space with a combat unit? Why can't missionaries and apostles just stack? It would open up entirely new strategies. You could stack five missionaries and send a missionary bomb at another civ. Potentially convert the whole city in one turn, at the risk of losing the whole stack if it's intercepted by an inquisitor. Instead we have units stumbling over each other. Detour off the road, get back on the road, detour off the road, get back on the road, holy crap this blows. Why can't the devs ever compromise? Units from different civs can stack on top of each other if they're at peace. How about that? That would alleviate traffic jams. That would let me send my units down the road and not constantly have to detour. Or how about this? You can combine as many units as you want into a single stack called a March, and the whole March can move together. However, it has no combat ability and it is vulnerable to attack until it is unstacked. Maybe you have to pay upkeep on it, so it's a good idea to only use during deployment situations. Would that be okay? Just to let your armies get from point A to point B? Just to unclutter the freaking map so you can travel around it? I don't get why these issues still aren't resolved yet. This has been a problem since Civ 5 and the developers all knew it. I'm extremely disappointed so far at this aspect of the game. I picked up Civ 6 hoping some of these issues would be fixed, only to discover, nope, they're still all there, and worse than ever before. Great. Just great.