I've been looking forward to an opportunity to use this movie quote so...
"overconfidence is your weakness."
Right now for ogres, it can be true. Many newbie bandwagonners believing that ogre net listing will be their salvation. This can be used against lists of ogre players and can certainly be exploited.
Low initiative - matters only when fighting something that can out-grind the ogres though....and this does lead to
Death and shadow magic - which can bypass our toughness and number of wounds with ranged effects and also targets...
Low leadership - especially away from the bubble. Forcing panic tests on ogre units is not that difficult and the more you can throw at them the more chance you have of a success...which brings us to
Terror causing foes - which force us to take fear tests in combats...again, more ld tests thrown at us.
Our flanks - we tend to have large ones and most of our advantages go if we get hit in them.
Again, everything here can be mitigated by list design and good play, but there are ways to catch people out.