I though there was some march mod like this, but after take a look i realized there is not. I wonder would be good a mod which makes the march works normal, but in the next turn it slow consideraly the army movement, like they would need to rest, like have only 50% or less of its movement in the next turn, assuming they should rest after the march, otherwise is just a infinite marathon. I wonder if its not a easier thing to do? People never supposed that it would be more aligned to the reality? Whatever.