Thank you for the sources.

The variance of RCS depending on design goals can be significant.



The variance of RCS depending on radar azimuth is much more significant in case of stealth, than in ordinary Alu jets, and RCS spikes are generally accepted in the design.



Radar wavelength also plays in the radar received signal power, and on long wavelengths the RCS can be 5~10dBm higher.
In case of active low frequency radar signal suppression (cancellation) is used, this effect can be small.



Flight altitude in case of B-2A, resulted total impunity during OAF, while the Yugoslavs had only low altitude Neva and KUB systems deployed.
Flying at 40~50kft even with the same RCS as the F-117A had, resulted slant ranges simply outside of Neva SNR capabilities.
No accident that from the 15th night of the war, B-2As were allowed to fly without package support, as NATO become sure that Serbians has no operating S-75M Volhov / SA-75M Dvina systems.
S-75M Volhovs were scrapped by the Dayton peace accord, SA-75M Dvina were removed from service years earlier.



Source of the charts: ADA464771 B-2 Systems Engineering Case Study
www.dtic.mil/get-tr-doc/pdf?AD=ADA464771

Further arguing on system capabilities that are under development (no public sources but just heavy marketing) or offered for export in the (far-far) future is always thin ice, I would rather avoid.

I hope, that most of you recognized that the S-400 system detailed here...
http://SimHQ.com/forum/ubbthreads.php/topics/4319049/Re:_S-300PS/PMU_(SA-10B_Grumbl#Post4319049
... is an export version with downgraded capabilities, where one aspect was already mentioned earlier.

DJT might be uneducated in military topics, but he is the elected commander-in-chief.