OK, after having made it through every scenario up to this point without having to replay more than one adventure, I have finally ragequit for the first time. I just cannot seem to get past the final monkey scenario (with the bridge and the mutant insect). I have died to this scenario over a dozen times now and have no idea what to try next. I've tried at least 6 or 7 different styles and nothing seems to be even remotely effective. How on Earth did you guys get past this mission?
Well, the first adventure seemed very much like tutorial for free move and blocking mechanics. That Attack of the War Monkies. Second one was same, and if iirc that is way you are facing. First of all, it is hard. Second frost spell or two for the "big guys" isn't all that bad while you deal with monkeys. But yeah, I think that adventure is the only one I had to restart twice.
Not sure if this is a bug or not, but if you use area of effect spells like Acid Spray, Flame Spray, etc, then Duck will fail to steal your card if it succeeds to hit at least one other target (but it can still prevent damage; it's one less thing they can throw back at you though). Not sure if it's just those cone based spells or any multi target effect, so maybe try Chops if you're playing with Warriors? I would honestly load up a wizard with lots of Winds Of War and Improved Telekinesis though. They're handy for putting a monkey into a compromising position where one person can smack it on the back, turn it around and then another can smack it from the other side. Just make sure you kite them a little first to use up their Move cards, because Free Move is a pain.
Encumber + firewall enjoy your simple win. This pree nerf was the easiest of all the monkey maps in the game.
One simple tactic against the monkeys: Wait for them to move. Even if the hairy buggers are already close enough to hit you, they'll still try to Scamper behind you - and end up facing the wrong way as a result. Duck and Acrobatic Flip are still block cards and won't help when you can hit from behind... And like Wozarg said, lava works great as well.
This is how I did it too. The mantis is slow. The hardest part is refraining from using attacks if the potential flip would be disastrous.
I use ground AoE abilities, lots of lava and a heavy armor warrior taking hits. Firestorm, fireballs, stuff like that.