I think it's actually less easy to balance than any approach that allows you to attack the guard posts separately. Balancing each guard post in a vacuum is easier than balancing every possible combination, even if you can guarantee they're all going to be stacked in a pile.
Actually no.
The current posts are balanced in a vacuum. Which is why there's a problem. It doesn't account for things like a Needler post showing up next to a Missile post (combined they counter something like 90% of all units, making them almost impossible to crack).
But if you assume that the giant blob has bonuses against "everything" then you can balance it because you know exactly the situation that it'll be in every time.
As the one who brought up the idea of moving all the guard posts next the home command, I don't want the other half of the change the guard posts require to make this feasible forgotten about.
Moving all the guard posts next the the AI's home command makes the AI HW a strength check, did you play the game up till now correctly? This then turns the AI's home command into a one-off fight that is over in a single attack (or two) that is resolved very quickly.
There would be no drawn out fights that take an hour (or hours) to crack an AI HW, the attack is over quickly either way.
Player wins? Nice work, that AI is dead.
Player loses? Your not strong enough, go get some more K/Fabs/Ships/etc. and come back and try again later.
D.
edit: Actually, that's a thought. For a quick-band aid fix how about this?
All the 'brutal' combat picks (tethuda,grav drone, wrath lance, I miss any?) get nerfed so they are not able to solo a fleet.
Remove the Core Fortress
Boost the AI Home-Command station so it has the health and 25% (15%? 35%?) the DPS of the core fortress, but no attack bonuses.
The intent being that this makes the AI Home Command station, which is the final thing you have to destroy, the most dangerous combatant in the system. So, rather then having it rely on other units to defend it, the AI Home Command is now an integral part of it's own defense.
This removes two of the big problems, the core fort shutting down anything not polycrystal, and the 'brutal' guard posts that can solo a fleet spawning close enough to another guard post that they are mutually supporting each other.