You know, I was watching Voyager Flashback and ...
I take it you haven't seen the Enterprise episode "Regeneration", where Captain Archer fights the Borg 200 years before "Q Who"?
But at the time of Q-who, Picard and the Enterprise E hadn't yet traveled back in time.
And Borg wreckage hadn't been dumped in Antarctic.
And historically Lily was probably aboard the phoenix warp flight.
And historically the NX-01 wasn't named "Enterprise."
And the NX-01 never encountered the Borg during it's voyages.
When Picard and crew were in the 21st century (FC) their actions and those of the Borg changed history. But there was a original unaltered
history prior to those changes.
At the time of Q-who, the original history was still in place