Who wouldn't be relieved to avoid Assyrian invasion?!

Earlier this morning (see here) I wrote about my befuddlement regarding YHWH God answering King Hezekiah’s plea to extend his life since it was during those additional fifteen years that his legacy would be tainted because he showed delegates from Babylon all his riches which eventually led to Babylon deciding to invade Judah after Hezekiah’s death (39.1-8). Bryan E. Beyer (Encountering the Book of Isaiah: A Historical and Theological Survey, 142-152) has provided a possible scenario that would make better sense of it. What if the prophet’s literary point is not written chronologically?

Beyer proposes that the events of 39.1-8 occurred before 38.1-22. In 39.1-8 the delegation is from the Babylonian king Merodach-Baladan seeking a political alliance with Hezekiah against Sennacherib of Assyria. Hezekiah becomes a bit arrogant as a host to Babylon’s delegates which provides Babylon with the insight they would use later to conquer Judea when Hezekiah’s son Manasseh is king. This makes more sense of Hezekiah’s prayer of relief in 39.8 that there would be peace in his day—that means Assyria would not win.

Assyria likely had already begun putting pressure on Hezekiah at this point and the prophet’s words that it would be Babylon in the days of his descendants that would conquer Judah was guarantee Assyria would not be victorious.

This may be the cause of Hezekiah’s boldness to go before YHWH in 37.14-20?

I wonder what the prophet’s literary motives may have been in reversing these stories? Thoughts?