Another angle from which to approach the question is that, to some extent, it’s similar to a question that’s been asked a few times on this forum by folks who’ve never played, which is: “which of the current A&A games should I buy first?” There are many possible answers, which all have good arguments in their favour depending on what priorities and preferences need to be considered, but one of the options I happen to like is to ignore WWI 1914 initially (or completely) because it’s a nonstandard outlier and, instead, to gradually work your way up through the following sequence: 1941 (the simplest global game), Spring 1942 (the intermediate global game), Pacific 1940 (the smaller of the two theatre games), Europe 1940 (the larger of the two theatre games), and finally Global 1940 (the most complex global game). So if training is one of your primary considerations, the best answer to your E1940/P1940 question might perhaps actually be 1942. It would allow your kids to learn to use some unit types that aren’t in 1941, rather than jumping straight to the even larger range of unit types in 1940 (regardless of which 1940 game you buy), and it would also allow them to get used to the non-infantry sculpt shapes that are used in 1942 and the two 1940 games, but which differ from the ones in 1941.