Finally back to this campaign. Built some more sophisticated defenses; Destroyed first stabilizer, triggering a raid with 3 diabolus and a bunch of other mechs; Killed them with only a few mechs lost. Then the mechs that were accumulating in the middle came, mostly centipedes, centurions and a bunch of smaller mechs; Most of these raids were pretty manageable, but now I have destroyed the second stabilizer... and uh...
Maybe we have gone a bit too far.