All good points and I would think the standard reasoning for those who would do such a thing. The idea I put forward in my post was a response to the unusual nature of the activity reported in the story.
But sitting here thinking, another scenario comes to mind that blends both. Destroy the aircraft in flight, but at low altitude over the city. Mass casualties, destruction, economic impact, etc.
Fourteen men seems like a huge number to knock it down. Two guys with the orthopedic shoes, in theory, could do that.
Perhaps there is technical redundancy in the boom-plan to assure its success, so as to cause a first disaster to draw cameras in to record some bigger cataclysm. Or, maybe the goblins' operation calls for a backup plan of horror, in case a takeover cannot be completed. Hence, multiple devices for such contingencies.
With that many operatives, the enemy seems absolutely determined that something happen in a certain city, and on approach.