If I were to exclude ltd eds.
If I were to pair my 372, the 249 would be on the top of my list for a 2-piece Panerai collection. Barring a 249, I would go with a 720 (I love the font).
If I'd go for a 3-piece combo, i'd have to pick out a 1940 case to match the 1950 and the only one that could do it is a ltd ed which would be the 587. Incidentally, there's no regular production 1940 equivalent to the 372 as well.
But as you guys said, there's no making mistakes with base designs. I've tried on the 721 and it is absolutely a gorgeous looking piece.
Probably why I like the 372. I can probably sum it in these words, if I were a boutique salesman, 'the 372 best represents who we are and it is available in our catalog'. Kinda like the 1861 moonwatch in some respects. Or the submariner (barring supply issues). Kinda sums up my criteria for buying watches asking the question what best represents this brand. Not quite easy to answer with some brands when they have multiple icons in their stable.
Thanks for the exercise, Nico
Best, Echi