First, I didn't realize Neonivek had totally moved the goalposts, but you're right, he has! In that case, yes, some luck is required.
But as far as fighting the boss - Kagus, the weapon rooms on the boss are entirely disconnected. A cloak + boards means the enemy can only effectively get off one volley before you take down (to begin with) their rockets, which you can then evade, and shortly after their entire offensive capability is rendered irrelevant. Literally every weapon room is completely isolated, and the final forms make it even easier.
The Cloak is what lets you avoid everything ELSE he can throw at you. Drone Waves, Super Laser Blast Attack, both are rendered completely irrelevant by the cloak. You simply go stealth and let it run it's course.
If you have both, and enough damage to overcome it's defenses even 1% of the time, victory is guaranteed, because boarders+cloaking means he cannot hurt you. The most he can manage is a stalemate which is (again) not a luck-based thing during the fight, it will be obvious whether you will or will not beat him by the time you get to him.
If you manage to get ahold of a bomb or missile of any sort, even as your only weapon (and you have enough missiles to use it), the stalemate is ruled, since you can blast their door control and juggle the crew down to 1 on the first form and then have your way with the things from there on out. If you have 5 points of attack, you can overcome through sheer force of arms. If you have GOOD boarders (as opposed to just "boarders"), and you bothered to actually upgrade the teleport, you don't even need that.