Uh wow, you're just so clueless.
-The whole idea of a tactical cube is that its the most powerful type of cube, maybe you should rewatch the episode. Your understanding of "tactical" also seems to be lacking, it refers to military action and would therefore have supreme firepower and shielding (as we saw)
-The Intrepid class is more advanced than the Galaxy glass, but not more powerful. There's a difference.
-Its technology had been augmented by Seven's know-how, so what? Now it can take on the entire borg fleet just because it has a single ex-drone on board that's been out of the loop for 3 years? Does that mean Borg technology hasn't advanced or changed an inch in that time?
Would that be less absurd, making the crew utterly pathetic losers who barely survive run-ins with Probes?
What on earth are you banging on about now? There was no need for the intrepid class to be up against a borg tactical cube for the sake of the story, all it served to do was portray the borg as weaker.