One of their messup is the "scavenger" follower, who increases the reward of missions for garrison resources. For some reason they didn't consider stacking. For example the biggest resource mission rewards 175 resources, which is a lot, since a resource-gathering building gets 180 in 24 hours. Well, with scavengers, getting enough resources can be trivialized:
PS: this can be done with "epic mount" followers too, turning a 1-day long mission into a 3 hours mission.