I don't know how their defenses work, exactly, but it is possible that if two phaser beams (or something in that vein) which have been modulated differently from one another strike as close as possible to the same targeted point, the Borg cannot "cancel" them out at the same time. If there is some sort of "specific interferometry" at play, there would have to be limits on it. It'd take close coordination to make this tactic work against the individual drones.
As for applying it on a larger scale, their ship defenses seem to be able to handle the brute-force detonations of photon torpedoes and such well enough (aided by an obviously superior source of power), so it would still take some doing to make much of an impact with this method--which would make sense of both the relatively long running battle toward Sector 001 in Star Trek: First Contact
and of the relatively quick resolution when Picard identified a weak spot on which the massed fire would show rapid results.
I certainly must caution you that the baseball bat is unlikely to do a bit of good