Is a static building. I had a better ideia. The "bases" will be circles of power. When you dominate a circle of power, you raise your income. Do you know a trigger for this?
It makes no difference.
Just create a trigger: (Note that if I type "//" it means the following is a comment in plain text)
* Generic Unit event: A unit enters within x range of (static building 1)
* Condition: Owner of (triggering unit) is not equal to (owner of (static building 1))
* Action:
// Here we must only change owners if the unit is dominated - that means the current owner has no units near the static unit
* Variable - Set (integer variable z) = 0
* Unit Group - For each unit in x range of (static building 1) do:
* If (Get Owning Player (Picked Unit)) == Get Owning Player (static building 1) do:
* Variable - Set (integer variable z) = (integer variable z) + 1
// Now that we've counted the number of units, just check the value of z:
* If z == 0 then
* Unit - Set Owner of (static building 1) to (Owner of (Triggering Unit))
// done. Make a trigger like this for all your static units
This is not perfect, and by no means how I would solve the problem, but it should serve as a starting point
Good luck.