I call it "The Voltron Proposal"
If you think of me as the Black Lion who represents "Kaiser" to the Green Lion of Shireroth and the "Shah" to the Red Lion of Babkha, it adequately demonstrates the larger concept. Now as The Black Lion, I would be "Captain Keith" or The head of state/head of Voltron. Jacobus as Steward would represent "Darrell Stoker" as pilot of the Green Lion. Babkha as the red lion, would be piloted by it's Grand Vizier, represented by "Lance Charles McClain".
Individually, each "Lion" (State) is a force unto itself. However, if these forces were to come together under the leadership of the Black Lion, not even the combined forces of planet doom could stop us.
Here's a concept photo of the potential power of the two independent states of Shireroth and Babkha coming together to "smash it up".
In short, the potential power of a number of sovereign states coming together when necessary under one Monarch could out match any rival and avoid the problems associated with unions and federations. As you can see, this is not a merger, this is cooperation with a gigantic kick-ass sword.
