La-5 is maybe overmodelled, however MBI publication is only a single source of data. I think that in terms of numbers La-5F and FN are just fine. However it needs to be taken in account from which series is the aircraft. Early La-5s might be inferior to later La-5s and the same goes for F and FN, there were big differences in performance as quality of production and materials improved.
There is another problem with La series and that is that La-5FN is practically unstallable (compared to La-5F or La-7 there shouldn't be a difference aerodynamics/weight wise). As I found out LA-5FN flies at lower AoA at the same G compared to F or LA-7 and is probably lacking inertia in some axis.
I've reported it to DT with tracks, they acknowledged it but I don't know if they will deal with those flight models. Russian aircraft are not too popular sadly despite the focus of the sim
Regarding other russian aircraft - we have more spitfire models than Il-2 models while the sim bears the name Il-2. I've also proposed several times that a simple adition of full metal late Il-2 type 3 could be at least included in the sim and would make valuable adition.