The difference ?
It's a freight forwarder's job to move boxes from A to B no matter what, it isn't a tactic. If the carrier of choice is struck, find another, if there's enough volume, charter a plane, it's just business.
Or do you call it a tactic when SLF and their travel agents attempt to find alternate ways to reach their destinations when their carrier is struck and they're stranded ?
I think striking employees should not be replaced and picket lines not crossed, but I also think customers have the right to make other arrangements.