The information paradox, the individuality sense and that biological virus from VOY are completely different weapons:
It's common sense that a biological virus won't spread beyond a ship;
Enterprise's crew predicted the borg security measures will most likely neutralise the individuality sense attack - which happened.
Considering the 'intimate' experiece both Picard and Data had with the hive mind - among other things - you can be sure that, by the time of 'I, Borg', Starfleet had a pretty good ideea about how the hive mind operates; an incomparably more accurate image than the superficial knowledge you have even NOW.
Everyone on the Enterprise was SURE the paradox program will manage to dismantle the hive mind, go around its security measures. Frankly, your opinion is worthless by comparison.
The paradox had a very good chace of objectively working.
And, indeed, Picard was CONVINCED the paradox will work when he made his choice. PICARD INTENDED TO CONDEMN TO DEATH AND ASSIMILATION BILLIONS UPON BILLIONS, the borg's future victims. All so that he can fanaticly claim he 'always' took the perfect 'white' choice. Monstruous.
PS: You're the one who claims to know 'everything' about the borg - far more than Data or Geordi - when, in truth, you only have a ridicuously shallow knowledge of their tech. Not me.