I'd argue that even with the request constructor, it is still too micro intensive.
Proposed solution:
Allow a planet to sponsor a starbase the way it does a shipyard. While the planet is sponsoring a starbase, all military production is diverted to that starbase (ex: it cannot sponsor the shipyard). The fall off penalty should be a bit smaller than for shipyards (say within 10 tiles of the planet then -10% per tile after, so 20 would get 0 sponsor ship).
Also, in a hurry, people should be allowed to "buy" modules the way one can buy constructors.
So there will be 2 ways to build a starbase module:
- Sponsoring by planet
- Constructors
It would (hopefully) reduce the Micro. There should also be an option to "auto upgrade nearby starbases" for planets when the shipyards are idle.