The connection of Borg to V'ger makes a lot of sense, though it doesn't necessarily have to be so. A shame that the writers in TNG didn't think of it. Course, the change of the Borg after Q'Who from only being interested in technology to one that assimilate everything is the worst offense and entirely within TNG so has other issues.
The strange thing is the Borg apparently assimilated the bases along the Romulan Neutral Zone (stardate 41986.0)...and then went off for a cup of coffee or something. The even weirder part is in Q'Who Picard references the earlier episode. So the Borg were already
aware of the Federation's existence.
So just what was the Borg cube that had been supposedly picking up Starfleet bases along the Romulan Neutral Zone like Pokemon doing with itself?
It left, and arrived at J-25 because it was unsatisfied with what it found at the Neutral Zone. Then when Q teleported the Enterprise to J-25 it got curious and wondered how it could do that, and when the databank search it did failed to yield answers it decided to go back to the Federation to see what it missed.
Weird thing is, once they assimilated Picard they'd know that it was Q who did all that but they still wanted to assimilate the Feds. Guess they figured if the Q were interested there may have been something worthwhile about them.