This is the second game it's happened. It's very frustrating. I feel there's nothing I could do. If anyone has any suggestions, please share.
Basically I'm playing Realistic Hubs 80 planets against 2 Diff 8s, one Rand Harder, one Rand Moderate. Playing with these settings, means I often get large waves that completely wipe out my wormhole defenses, so I'm often left with none. This means units that can ignore force-fields slip past. These then take out at least one harvester which I can do nothing to stop. In both games they managed to take out 2-3 harvs, and well, they just rushed me, and the amount of ships they attacked with combined with my crippled economy (no harvs) meant death.
First game was against a Shadow Master (moderate one) and Spec ops. This meant infiltrators and lots of units coming into my system. By the time I realised what was happening, I was down 5-6 harvesters and I was dying, with no economy to stop it. This is simply because the infils bypass the exo-shields, ruining my economy in a fraction of the time the other units would. This happened around the 40 minute mark.
The second game was similar. I kept getting hit by large waves, lots of parasites and stuff that fighters counter. I didn't have tech for fighters 2 (silly me), but in the end I don't think it'd have helped. At the crunch, around the 1h20m mark (just killed an extra planet... so many waves), I got hit by a "168 unit cross planet attack" that turned out to be 1,200+ ships (bug?). A few of them were eye bots and vamps. About 2 minutes into the attack, I had absolutely no harvesters. They were all dead. All the attacking units were stuff like parasites and raiders - nothing that can kill exo-shields quickly - with a few ignore shield units, which were maybe %1 of the force. Due to my simple lack of economy I lost any chance of surviving. I had no resources to produce fighters with to counter the massive amount of raiders and cruisers. My slim chance got obliterated to nothing.
I think exo-shields should block all units personally. Up the ongoing cost by 50% (or even double it), it'd be worth it.
Also, I wasn't sure to put this in the Suggestion forum or not, so move it if you wish.
PS: The second game, AI were mad bomber and unknown. Never found out, gave up when I had nothing to fight with and a 1000 ships pelting at my home station.