There he goes making ridiculous assumptions about being right.
As I'll continue to point out, the Terran campaign features an Overmind which RULES over the cerebrates. The Brain Bug WAS NOT the main antagonist. Rather the entire race of arachnids was along with some more in depth look at the gruesome world of the Federation but that's off topic.
The Brain Bug is more appropriately contrasted against the cerebrates of the Starcraft world simply because of the fact that the movie states the probability of so many more existing. If we were to compare the idea that the Overmind was similar to the Brain Bug you'd have to have some sort of lower caste underneath the Brain Bug but higher than your average Arachnid warrior.
Additionally, no drugs and/or tranquilizers were used in the capture of the Brain Bug (in Starcraft, medics are used to inject the needed chemicals). Also of importance, Casper Van Dien, while the hero, did not capture the Brain Bug. He was too busy saving his ex-girlfriend (WTF? Why bother?) and that is why Private Zim (formerly Career Sergeant Zim) captured it.
My logic is, while not infallible, quite thorough.