As default of having a better way to show what i want, the subject ended like that =3
Having the ability to choose for the oncoming month (as it's too tcheated to be allowed to do it at will) what as an overlord you want to focus. Which in result would let's say increase your production % but lower your army might.
Ex: Warchief : +20% army atk/def & +20% production time. (+ as in increase, so make your production slower)
Warmonger : +30% army atk/def & +40% production time.
Farmer : -20% army atk/def & -20% production time.
Raider : Increase drop rate in Raid but lower it for dungeons.
Novice : Increase N dungeons drop rate but lower HD and raid.
Adventurer : Increase HD drop rate but lower ND/Raid and maybe even give a malus to production for this one to balance thing a little.
Explorer : Increase Dungeons drop bit quite a bit but lower army might and maybe even increase dungeons time, as they would look more carefully than usual.
It's not the choice who lack i only put some there but there could be a lot more than that. Some could be free, other could either need to be researched/oracle or unlocked by doing a task/achievement.