Triggering on "offense" is one way of designing away from the possibility to not be used. Some things that you have become rattlesnakes in the multiplayer format. They say, "don't come over here", they discourage an attack, and so the impact it has on the game is that they -don't- do anything. This can still be proper balance. The thing is to notice that tools can change the game in a whole bunch of ways, make sure they tilt towards what you actually want. And 'Crusade' being at all for a moment applicable without, y'know, taking the crusade to the infidel's land is not an appropriate form of such a policy. Of course some of your titles aren't serious. Triggering in enemy territory means this will not happen on defense and it will not at all have any use or relevance to someone who is not pressing to activate it.