I also did the math. I was there on a cloaked ship ready to take the positions and move the turrets. I also saw that many of those ships were shooting prims because the base turrets were nailing them when they got closer and they couldn't shoot cerbs not to mention that they didn't shoot it at the same time because of the weapon platforms shooting back. You can even see it on the video in the topic.
Edit: They didn't have that kind of BS force. Plus they had Cruisers, GBs and repair ships which ment they had less BSes.