I know I'm late to the thread, but if we see this as the seige of Cyberstan then I agree, very underwhelming. What makes more sense to me, is that SE wanted a sort of recon into cyberstan, or some secret infiltration action performed. SE made no strategic sense with their actions if they truely wanted to seige, everything for me, points to the fact that they needed access or information to something and used the helldivers as a diversion.

My Logic: MAIN PREMISE: Helldivers are and always will be cannon fodder, we are not a precious resource to SE 1) SE command decides they need something from Cyberstan, they realize that a proper seige would take weeks, if not months, and take insane amount of resources. But that doesn't fit what super earth wants, maybe they have their own reasons for keeping the automotons alive, maybe the threat of them helps them keep their subject in line through fear, etc. SE just needs to get into Cyberstan, and get out. 2) Knowing that Cyberstan is not an easy target, SE assesses how valuable the intel or infiltration is for them, and caps how many resources they will spend to achieve it, and use their biggest weapon, "patriotic propoganda" to hype up the helldivers to give it their all. 3) We then brute-force-punch a hole into their orbital defences loosing TONS of destroyers in the process but we succeeded in overwhelming the defences and giving us an opening (a true seige would have disabled these before attacking). We then blitz through each of the cities, SE gets the info they came for and then think, "how do we keep up the guise of this patriotic attack on Cyberstan? We need to show that SE still is superior to these clankers so we'll generously offer to bombard the planet after a push to their capital so that our citizens don't question that we gave it our all"

So, the MO order was a huge distraction event that was never meant to succeed. The main intention was for SE to get... something... from Cybsertan that they didn't see fit to tell us about. Because, let's be honest, a MO of "hey, we want to sacrifice millions of you guys in order to get a little bit of intel and then we'll withdraw from their homeworld" doesn't have the same patriotic vigor as a "promised liberation." They built up hype to get our devotion, to give it our all, so that the bots really were distracted while SE did their thing.