Housing beardies together is never a good idea. Sometimes, we misinterpret bearded dragons' behavior or try to give them human qualities. What may seem like cute, innocent behavior, is actually a display of dominance. For example, when beardies lay on top of eachother, they are not being cute, they are competing for dominance. It is not always fighting and aggression. One beardie will usually win out and get the best food and light, while the other lives in its shadow. They are solitary animals and they don't want a friend.
If you house two males together, they will fight and at least one will end up dead.
If you house a male and a female, the male will continuously try to mate with the female and cause her stress.
If you house two females together, you MAY get lucky, but more often than not, you will get two beardies that are constantly competing for the best food and the best lighting.
And don't forget, if one of your beardies gets sick, it could very easily pass on illness or parasites to the others.
If you want to see more of why two beardies should never be housed together, read this thread:
viewtopic.php?f=6&t=154908