Just a guess, but I'm pretty sure RAZBAM has been big in the FSX sim, so perhaps a lot of the development of the M-2000C can be thought of as a "port" from fsx > dcs. I Don't know for sure, but they're an established sim maker whereas some of the others are just starting so that probably helps a lot on development times.
Also, it's always going to be different based on the actual tech they're simulating. For the F-14 something that seems fairly simple like variable sweep wings is actually insanely complicated aero engineering.