I have 2 Queen l asius niger with 3 workers and are peaceful, and nothing you do not
sorry for my bad english :lol:
Time will come and workers will chouse which queen to kill.
I've tried this myself, its ok when there are a small number of workers as they can't take on a queen, but when there are alot of them, say about 20 they will some how kill the other queen and yes sometimes you are even left with no queens at all.
You can have two queens share a brood but when the brood has hatched they will kill one of them.