Surely on or two could have hacked the Borg network morequikly and effectively than Data Though I d suppose there's a danger of the BYnars being tempted to join the Borg collective
I think their timidity would make them reluctant to cooperate with the Borg. Once access to a Borg Ship occurred through proximity (like in battle), they would be very helpful in diagnosing, then creating covert programs which could be transmitted to the Borg Computer, which would disable Borg resources. Information which was collected when Data "interrogated" the Borg Network via Locutus, should have a positive impact on those objectives.
The Bynars are pretty close in general concept to the Collective anyway, so I can see them as an early target for assimilation. Whatever they could come up with would make them a threat too, given those similarities; but assuming the Borg adapt against it, I don't see them making too much of a difference as their technological advantage wasn't very dynamic. Mark