Very interesting indeed.
So here the WT has worked backwards from their fallacious 607BC/1914CE chronology to arrive at a contrived date with zero secular evidence for when some ancient event purportedly happened, in this case being:
"The Watchtower publication assumes: "The 390 years of Israel’s error evidently began in 997 B.C.E., the year that the 12-tribe kingdom was divided into two parts." "
So what do scholars and secular authorities say as to when the 12-tribe kingdom was divided?