At first I thought this was an ingenious idea, but I tried it and it didn't work, at least not in DL 1.5. To test it I whacked the AI down to its last planet and moved around 100 constructors into an area along with 300 huge ships maxed out with weapons & defenses. I ended the game by taking their last planet and recorded the score. Then I reloaded, went 10 turns doing nothing, ended the game and recorded the score. Finally, I used the constructors to build 4 maxed out military starbases right in the middle of the 300 huge ships, boosting their stats, and THEN I went 10 turns and ended the game. Comparing the scores, there was virtually no difference, even a very slight drop in the starbase array scenario (probably due to using so many constructors). So I think this is a non-issue in terms of people using it to boost their scores. Maybe it worked in a previous version, I don't know, but it doesn't seem to work now. Just FYI.