In other words, starbase benefits should not stack with other starbases. Otherwise, 90% of the time spent on games will be building starbases to surround your planets (which is a rather tedious chore).
Currently the dominant strategies are either:
1. Colony spam.
2. Starbase spam.
3. Do both.
100+ planets with 5 starbases means the construction of 500+ starbases. Each starbase requires at least 8 constructors for a total of 4000 constructors. Each constructor takes about 5 seconds to move to the appropriate starbase, meaning that it would take 20,000 seconds or 7 hours to build 500+ starbases in a game.
In other words, the game effectively devolves into building colony ships so you could build more colony ships so that you have more colonies so that you CAN BUILD MORE COLONIES FASTER. And then after the colony rush is done, the game becomes building constructors so that you could build starbases so that you can build constructors faster so that you can build EVEN MORE STARBASES FASTER.
Personally I think the developers should create a minigame on who can spam out constructors the fastest. To be honest it wouldn't be all that different from the game right now at certain settings.