Couple of points:

1. What exactly determins military value for the graphs. Now I have read many contradictory things about this here, it is attack plus defence plus hp, it is just attack, just attcak plus defence or even just the number of ships. What is the truth now with 1.1? Is it effected by difficulty level?Getting a decent lvl in masochist is impossibleuntil you are just about to win it seems.

2. I was reading in the journals that AI only designs new ships once a year. This might explain why some games turn out as a walkover.
Imagine this. AI has low tech, designs low tech ships, BUYS tons of them and researches ike crazy but by the time redesign time comes it has busted its economy and cant afford to build many of the good ones and cant afford to upgrade the old ones. This would especially apply to races who are heavily presured by influence as they would have scrapped many factories in favour of influence buildings or even farms.
Of course some games this might just happen to one race, especialy on high difficulty so the games are still fun but I think the AI needs to design at least once a month. OK maybe several times a year if it pressures the cpu too much.