I've heard that this objective might not be the best cause if your opponent picks it and you make the mines tough on them, that it can lead to non games and that's bad because you need to score a high mov in order to place...
But if your opponent also knows that she has to score a high mov than either they pick it and say welp, I guess I gotta run over some mines... or perhaps they don't pick it at all fearing a non game and thus forcing them into your more favorable red and yellow objectives...
Thoughts???