You're trying to make the argument that 80% of 100 is bigger than 15% of 1,000.
No one is buying it.
That situational benefit is HUGE when it comes up, absolutely MASSIVE.
For example, I once had a wave of ships attack a planet where I had a military command station under a FF mk1. I don't know why I didn't hear about it, but I didn't. Anyway, an hour later* the "command station under attack" warning fired and when I peeked at the system there was 200 enemy ships scattered all over the entire system.
I was able to bring my fleet in and clean up long before the command station was in danger.
Had that been an econ system? I'd have lost it, and likely the next system too.
*Total guess, but that's about how long I think it took them to knock down the FF, given how unfocused their attack was.
If it were a "wave" with diff 7 or greater with over say 300 aip then any lvl of military station could not hold it off. A military station in its mark, over a hour of time, can hold of 50 * mk of com station ships maybe. I get waves of 150 on ultra low caps with 200 ish aip on difficulty 7. I don't know if you too play super low caps with low aip, but otherwise it didn't hold a "wave". It held border aggression, which as I said, the military station does well.
and what if you did lose it? 200 ships are nasty, yes, but then you zip your fleet in. If you put even a single shield over your worlds that border border worlds they usually stall at least 3 minutes. More then enough time for the fleet to zoom in and clean up.
So assuming your initial proposition is correct (for I do not know the whole story).
If you acted rapidly from the very moment you saw the first world fall, be able to rebuild it in 10 minutes. Since you said you somehow held the planet from a wave for a hour, then you have at least 50 minutes of where the econ is supierior to the military station (because that is when the next wave hit). Which comes out too...300k in m + c
per planet. if you compare a military III to a econ III. And while those planets are doing their thing, your other 4 econ III planets are shining the military III's by 360k per hour per planet.
And there is nothing wrong with putting military I's on your border worlds if for some reason you don't put defenses on all of them.
Perhaps, then, it comes down to if you play defensive or offensive, and if you try to keep inner worlds or not.
If you are defensive and have no inner worlds, military stations can be better.
If you play offensive and/or have no inner worlds, economic stations are better.
Which still leaves my wondering what to do with those logistic stations.