The FC Cube was weaker than the one in TNG: In TNG they Armada couldn't even scratch the Cube whereas in FC they were able to do damage to it before Picard told them where the weak point was.
The FC Cube was still smaller than the one from TNG.
It was still depicted as an utterly hopeless battle.
So it all comes down to "Yes, I need them to spoon feed it to me that the Borg ships were weaker than the massive one from TNG."
Again you're implying that this was their intent behind it, and I'm simply too thick-headed to pick up the subtle clues they left. There were
no clues because they weren't
trying to depict that. They can't spoon-feed food they don't have.
If I were you, I'd stick with T'Girl's angle which says "what the producers intended doesn't count, only what was on screen is canon." That
, at least, is capable of being defended. What you're
saying is provably false.