From my experience in my games my ability to beat the living snot out of the AI's early in a small universe with max AI's at max diff. and bonus was mainly because I built alot of base space yards the first thing I did and then flooded the AI with smaller technically inferior ships so sheer numbers killed it.
So I thought, what will happen if I teach the AI to build alot of base space yards? Well, now I know and it aint pretty. I'm actually on the defense in my homesystem fighting just one AI. And it's kicking my ***. There is one system between my homesystem and the homesystem of the AI I'm fighting and I had two colonies in it and was actually pushing the pace in the AI's homesystem attacking it's homeworld and destroying it's base space yards. But I made a mistake and let a salvo from the weapon platforms land on my fleet which crippled alot of ships in range so I had to tuck tail and run with the remainder. They where hunted down and destroyed by a second AI fleet coming from another system and since then I've been on the defense. One of my colonies in the system between us killed several single destroyers and light cruisers with it's weapon platforms until the AI finally attacked with enough force to wipe it out.
The only thing that kept me afloat at all is the fact that I moved ship capture up one notch in military science so I had it available from start. If I hadn't been capturing the AI ships and analyzing them I would have been hopelessly behind in technology years ago and probably dead long since. It's now 2404.0 and the AI has pushed me into a defensive position in my homesystem. I hade a fleet of 12 ships of which 8 where fighting (the rest troop transports and repairships) annihilated just after they captured an AI planet. The AI glassed the planet of course. Just Last turn it actually attacked my homeworld with a fleet of 7 superior technology Light Cruisers and I expected that to be the end of me as all I had to defend the place with was 3 inferior Light Cruisers and 5 Weapon Platforms. My entire shipbuilding infrastructure of 5 base space yards was going down the drain just one year before they finished building the latest Light Cruisers in my arsenal with upgraded shields courtesy of the Sergetti Empire (the AI I'm fighting).
But due to AI stupidity in choosing it's targets I won with minor losses. All weapon platforms, about 500M people and 4 facilities (including the planetary space yard) are my complete losses. I held my 3 fighting shpis back close to planet so the planet and the ships could work together. The AI fired at the ships when the planet wasn't in range but as soon as the planet was in range it's just like the AI forgot anything else even existed. It shot only at the planet, even after the weapon platforms where gone leaving my 3 inferior ships free reign to bLast all 7 AI ships to pieces. Had it instead killed my ships (which it could have) and the base space yards it would have crippled me. Now the follow up fleet of 6 light cruisers right behind the first one will meet with my 3 old ships and 5 new ships I wouldn't have had if my base space yards had been destroyed.
But still, the small changes I made has given me a pretty good fight out of the AI. Had I been fighting 2 AI's at once I doubt I would have made it this far. Thankfully my homesystem only has 2 warp points of which one leads into a black hole with all warp points in/out of it causing damage. Not many ships coming through that way, thank the lord.
I have also tried to get the AI to research, build and use troops and armor but it doesn't seem to work yet.