The article makes a number of insightful points, and I especially appreciated the emphasis on God’s unexpected response to violence: non-violence.
May I, however, suggest that God did not act in a covert way in this situation. I would submit at least three main arguments:
Jesus’ birth was foretold - when asked, the religious scholars were aware of it and able to quote Scripture. The fact that their expectations were not met in the way in which the Messiah arrived, was no indication of God’s attempt to go behind their backs. The religious leaders knew.
A cortege of foreign dignitaries arriving at the palace was anything but covert - it was as in your face as one could get. The political establishment was informed.
A choir of angels \ a bright and new star \ increased angelic presence could be classed as extraordinary, especially as the Word of God has been scarce for the past 400 years. In this instance, coupled with the testimony of the shepherds, Anna and Simeon, to name but a few, the Word of God’s arrival was well publicised. The regular people knew too. Jesus burst on the scene and everyone who paid attention knew (though, they may not have understood it at the time).
One side note: personally, I find the war metaphor unhelpful. It may have support in the Bible and a whole lot in our various theologies, however, it may be worth exploring different ways of explaining good and evil \ sin and righteousness \ right and wrong, etc.