The only way I think an evil kingdom would work is if on the outside they looked normal, but on the inside had their own assassin/smuggler guilds. Under ground arena fights and gambling on those fights. Secrete phrases to get in and out of those areas. They could take the time to plant some of their players in other areas.
For example.. Right now.. there are guilds in other kingdoms looking for ways to have outlets in other kingdoms. Lets say you join one of those. Because of that connection, you found out some item is going to be transported to Kingdom C. You notify your home kingdom of this transfer, the when and the where. The kingdom mobilizes the assassins/mercenaries to jump the caravan and retrieve that item(s).
Then, once the mission is completed, they return home. Maybe, that item then gets auctioned off on the black market or maybe someone paid for retrieval of a particular item.
The kingdom would have legit sellers to handle the actual transactions all the while protecting their illegal endeavors.
So, I think it could work. It will be some work though.