I'm beginning to think that that GSC Cult base was deliberately disabled by the 40k team because it is rouggghhh, at least with the Space Hulk you get a nice little warning about what you have to destroy
I can say the same about traitor guardsmen bases, I went in with drop pods and the first thing I see is like 10 sentinals all armed with missiles, with all the explosives that slam into my landing zone, I would be lucky to have 3 marines alive by my 3rd turn.