urely this whole adaption thing is a bit 'bogus' im sure that you can't adapt to everything so quickly and the things you can adapt to might be difficult or impractical.
Given all the enhanced Borg physiology and looking at how smart Seven of Nine of is and with their superior technologies, I think they can somehow manage, quite well.

Seven of Nine is even smarter than your average Vulcan with lightning fast reflex, typical of Borg.
And Borg adaptation is part of the rules of the game here. Why complain about that and not other bogus technology such as transporters and warp drive?
My solution is "fight fire with fire." The Borg attack via nanoprobes, so build self-assembling nanoprobe weapons that can be piloted remotely, keeping humanoids far away from the battle. The Fed nanoprobe weapons should be able to break apart and re-assemble into anything required, from a starship to a knife.
Unless the Borg have nanoprobes that can infest other nanoprobes (how would they fit
inside other nanoprobes?), they've got no advantage and it just comes down to a slugfest. With Fed replicator technology, they can produce an infinite supply of nanoprobe weapons and keep the Borg indefinitely at bay if not go on the offensive.
On second thought, the remote piloting by humanoids would be the weak link in the chain, since those communications can be disrupted. So the Fed nanoprobe weapons should also be able to function independently if communications are interrupted.
Of course that raises the possibility of Fed nanoprobes becoming sentient and getting bright ideas, but that could be an interesting story possibility of its own.