Great concentrated information Hpasp.

Where in this history would Armenian and Azerbaijani S-300s appear? As far as I know Armenia had a older, apparently S-300PS system and recently got a S-300PMU1 or -2. This was apparently to get on pair with Azerbaijan who got at least one brand new S-300PMU2. Little note, given the good relations between Azerbaijan and Israel its possible that they had the chance to take a look at or even train again the S-300PMU2 and pass the info to the US and hence NATO. However I have doubts whether Russian intel and influence on Azerbaijan would allow this to happen.

A few more details: Apparently East German air defense troops were not aware of a operational S-300 there as far as I know. Either its was still packed before being send back to the Soviet Union or some secretive unit operated it in its short presence there.

Iranian S-300PMU2's use the command post shown in your S-400 illustration. Given that Russians said that original 2007 were reconfigured and sold to other costumers and the 2016 batch is said to be newly produced, could the Iranian PMU2 configuration be different to the standard S-300PMU2?