1. Commentators habitually skip over these comments, dismissing them either as "antiquarian notes" (Driver, 36f.; Thompson, 91-93, Mayes, 137ff.) or merely as "comments of historical interest" (Christensen, Deuteronomy 1:1-21:9, 43; Craigie, 110f.). T. Mann (28-33) thinks so little of them he elides them from his translation and commentary without so much as a word of explanation.
2. McConville, Deuteronomy (Apollos Old Testament Commentary, 5; Leicester: Apollos, 2002), 84. McConville's comment specifically relates to Moab; we assume that the same thought applies to Ammon as well.