Nice JA history overview. I've always felt like all official games after JA2 are best ignored as they only harm the franchise. The 1.13 mod however was the best mod for any game I have ever experienced, improving upon most of the game mechanics and features. The striking realistic weapon and weapon customization variety is what launched this game to my personal top 5 games. Xcom is great, but its formula would be a terrible oversimplification. I wouldn't want to play a JA which has just bullets (with no specific caliber, type, etc).
JA2 1.13 with modern graphics is everything JA3 should aim for. The other titles are just irrelevant.