Historical accuracy for a given scenario might be nice but we are so far from ever being able to do it.
We have a very limited set of aircraft and ground units in DCS and we have to make do, it's only relatively recently that we have been able to assemble a fun, reasonably balanced cold war multiplayer environment in DCS.
'90's viggens and '90's Ka-50s are a necessary evil in this environment, at least we know we will soon be able to replace the latter with Mi-24s in the near-ish future.