Thanks for the replys, I think it was an AI eye.
Game is much tougher with the "Realistic" map type as expected, and eventually I lost 20 hours in despite being on the gasp of my "grand fortress" plan working. A couple of notes from the game:
Armored Golems are really useful: High Armor piercing rapid fire attack lets it knock units short of tech 5 out quickly. I will beeline to them aggressively as I did this last game (I had to beeline to bomber III and use a 120 second EMP to knock the fort III guarding it, and it was worth it.)
**I hope other golems are cheaper to operate compared to the armored golem: They have less health and defense and the armored golem was expensive enough just from attrition. If others suffer from similarly expensive attrition I will not use them.
Missile frigates and space planes were almost regulated to defense halfway through: Their health/cost ratio made them too expensive for general attacking. Space planes are fast and attack hard, so they are good for defense just my economy could not support them contiously. Missile frigates were just fragile: I say this despite using shield barriers as my starter ship. Bombers were also regulated to this, but their useful near-immunity to fortress compined with heavy armor made them very handy when combined with shield bearers to strike fortresses with a significant enemy presence as needed. I don't know what to do about the frigates (boost attack and lower bonuses?), but for the starter triangle they consistently seem the weakest, and I always feel I get a break when the AI sends them toward me.
Resistance frigates and fighter/bombers are perfect the way they are right now: Saving and protecting resistance colonies is expensive and having them useful again makes it a worthwhile trade off.
When on defense, the AI preferred to hit armored golems over command stations, making them useful tanks. I doubt this is intentional.
After playing two mediums, I feel "sledge hammer" AI should go with medium as well. The waves are simply brutal because they sap your strength so much. Neither the medium nezul nor medium stealth user could compare with the demoralizing waves the sledger threw+ at me.
Now for my death: Swamped by border agression. The AI built up 3400 tech III ships and swamped my planet with a (1) tech I fortress. The fleet then went on a killing spree and steam rolled my fleet and core defenses despite making stands on two more fortress planets. My conculsion.
Firepower for forts seem off. My fortresses would show a colossal ~1400 firepower, yet they can fall to fleets (not bomber fleets, just general fleets) from 1/3 of their firepower. This makes what turns out to be the death of me: AI border aggression builds up so much on adjacent planets to fortresses that when the AI finally releases it you can have nothing to stop it. I understand border management is important, but being swamped from 3400 tech III because they overestimate the tech I fortress 5 fold when the AIP is at 300(II) in unnerving.
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Don't get me wrong, it is not impossible to get around it, just some creativity to fool the AI is in order. I am considering using a combination of station jammers and a particular planet layout to get around it. The planet layout would be like this
x
/ \
w z
\ /
y
planet w is enemy. x, y, z are mine.
x has 4 fortresses. y is lightly defended with few turrets. z has a planet jammer. Planet jammers / neutral planets would be used to cover other fronts.
y absorbs most runoff from w's planet aggression, while x absorbs enemy waves. z ensures that when a wave/ aggression hits y the rest of the planets survive. Fleet clears out y from time to time and a new station is rebuilt.
This tactic works on paper, but feels way too micromanaging / inflexible to get around using fortresses. Other ideas abound, but they always form a barrier between an AI planet and a planet with a fort unless their is a unit dumping planet alternative.
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As of right now fortresses are time bombs for border aggression. Border aggression due to an odd firepower reading. For waves the firepower issue is moot, but since border aggression is from firepower it is very important I feel to improve this. Odd firepower readings also occur for golems and starships, but at least they are mobile so it is rare for AI buildup to occur.
EDIT: Was able to load a save before the event: I was able to bait the AI using the armored golem: The AI focused exclusive on trying to kill it for 5 minutes, allow it and the rest of my fleet to slowly gnaw it to dust. It still left me 40 million resources in the hole and I cannot say I felt like I "won" but rather glitched to temporary victory.
EDIT EDIT: More precisely detailed the group that got me.