The most unbelievable bit about the entire thing is that the Colossus couldn't just lock onto the Sathanas's four main beam cannon spike tips and selectively blow the cannons away before they could fire. Then again, BGreens aren't all that good at aiming...but still...in a situation like that, the very commander of the Colossus himself would probably aim the guns manually... I wouldn't trust a lieutenant gunner with aiming those BGreens, I'd have four joysticks on my Command Chair specifically for each of them. =D
Off topic stuff aside, and trying not to overfuel this thread's fires, it would have been interesting if the kamikaze were done by an overload (or uncalculated engagement) of the Colossus's jump drive, causing it to jump out INTO the Sathanas, exploding inside and outside the Sathanas simultaneously, causing an apocalyptic explosion that blows both up to smithereens.
Also, who says the Shivans are accurate with their jumping? Here's a way to finish that mission REAL quick: Sathanas jumps in and hits the Colossus in the process...both go boom or sathanas survives with 5% hull at which point some little measly group of Deimoses fleeing the system show up and have the satisfaction of blowing it to hell