I'll make a test map and find out. Give me a few minutes
Alright, mine count can't be altered via modifying hangar count. I've attached the map I made to come to this conclusion.
Now, that doesn't mean it's not possible. What you could do, is instead of altering hangar count, simply have a location center over the vulture, remove it, and create a new one, which will have 3 mines.
Reply if you have any more questions about any of this.