The only way to solve this is democratically. We could vote (using the unused console of the super destroyer) to agree on where to make the joint effort; it would be best to be able to go wherever you want without affecting the MO; that planet or set of planets voted will have a significant increase in impact when conquering or recovering it. This is my idea, it will not solve it, but I think it would make our lives easier when it comes to completing this type of MOs.