The key to taking on Traps MMs is to use snipe attacks to beat their range, or to get at them before they can lay down their toys.
I have a Mercs/Traps MM at 27 on Freedom, and once I lay down the Mortar, Poison Bomb, and Healing Beacon, I laugh at all comers.
I have a Mercs/Traps MM at 27 on Freedom, and once I lay down the Mortar, Poison Bomb, and Healing Beacon, I laugh at all comers.