It sometimes seems in WW we're operating at a level of standardization equal or greater to that of 2010, rather than 1940. Alliances are standarizing on tank designs (something that hasn't happened outside the Warsaw Pact), countries standardize on a single cannon for common use across the Navy and Army, etc. There's a value to standardization, yes, but it can be carried too far. Certainly, there were period cases of re-use of an already existing system, but in many cases that was because of a time-constraint: the country needed something quickly and used something it already had as an expedient. But it does feel, at times, that we're putting even more weight on standardization than the current world does, let alone the period of the 1940s.
All just my opinion, of course.