I don't think it's possible to really effectively play this game as a hero and an overlord simultaneously. Some overlord cards (like Dash, Frenzy, or Dark Fortune) help out the OL. However, there are trap cards (like Poison Dart, Tripwire, Pit Trap) which are really only effective if the heroes don't know you have them. If a hero knows you have Pit Trap, that affects how he moves. If he knows you have Poison Dart, that affects who opens a door or searches.
With regard to setting prime objectives, that also doesn't work. There are several quests where the actions of one party force the other to change its objective, in order to make the most of a bad situation. For example, there are encounters where the OL may have made victory very improbable for the heroes, so they abandon the quest objective and search for treasure. There are others where the heroes are likely to win, so the OL decides to go for knockouts for extra threat, or defend treasure spots to prevent them from searching. This is even more complicated when there are multiple win conditions ("If A or B, then the OL wins.")
Spawning the minions is a no-brainer. Moving them around and acting with them is not.
Edited by Zaltyre, 28 August 2014 - 02:04 PM.