This is a pretty typical selection. Psalm 20 is a prayer for victory in battle. As odd as such prayers are when referring to sporting events--for instance, we attended a Newman Center where the priest always offered prayers for the Cubs--it is actually kind of gruesome when referring to battle. But, also more important. When we falsely claim that there are no atheists in foxholes, I believe the fantasy is that the soldiers is praying for his life, not the death of her opponent.
I did not catch any difference from 2 Sam 10 and 1 Chron 19. The Ammonites still (again? I lost track) hold the city of Jericho. David sends some folks to give his condolences to the new king for the death of the old king. There is a misunderstanding and pretty soon armies are advancing, including mercenaries from the homeland of Abraham.
I noticed that the Spanish translation uses "sirios," or Syrians, while the English translation uses "Arameans," or arameos. Because we live in the computer age, I searched the frequency of each term and it breaks down like this. NIV uses Arameans (plural) 48 times and never uses Syrians, although "Syrian" is used twice in the Gospels. NVI uses sirios (plural) 55 times and arameos only twice, both Old Testament. It also uses "arameo" (singular) 17 times. And, most interestingly, Laban & Abraham are both referred as arameo.
Clearly justifications for using either. I have a friend who is Persian. He said his folks were Iranian until around, oh, 1980. Then they became Persian again. I wonder if any Syrians have strarted identifying as Aramean?