If God is possible then Gods are possible. Because it is all in one's mind.
Being in one's mind and only in one's mind does not make it fictitious. For example,
Thoughts are only in one's mind, still they are not fictitious. Memory is only in one's mind, still memory is not fictitious.
Going one step even further, and see the big twist here...
even PERCEPTIONS are only in one's mind, yet they are real!!!
The Hindu concept of maya stems from that last axiom I think
You cannot have many Kings running the same Kingdom as it is bound to casue problems in power sharing.