I didn't know Rise of Rome was a new expansion!
It's quite a stupid bonus, laming is already too easy to do because if you get lucky and your opponent has front boars, there's very little they can do. The amount of laming in team games is ridiculous. On one hand, players are too sloppy, rigidly adhering to build orders that have them take boars after four sheep and such, but when everyone has the Mongols, lamers bear very little risk in going forward. The Vietnamese might even be worse, because at least an eagle warrior has to find your base before he can take your resources.