I think you have something but I think they could also try building to cost instead of function. There are also advantages in everyone using the same equipment

I think you have something but I think they could also try building to cost instead of function. There are also advantages in everyone using the same equipment (even if cheap) and some way needs to be found to buy in larger batches without demanding the union set of the features that each nation wants. Somehow it also has to keep some national capabilities alive otherwise it will be unpopular. Think of Ukraine - it needs replacements but has to get soviet stuff because that's what it understands. It is an inconvenience really isn't it? NATO can't just send them some Patriots or F-16s.