Do you ever contribute anything meaningful or technical? What is the hit probability of the MKV? Can it engage low flying targets? (likely not). Can it be quickly deployed? Can it engage multiple targets? Is it maneuverable? Does it have ECM?
The MKV is built to knock out satellites and this is it. The S-300/400 is built to shoot down aircraft/cruise missiles. The MKV would be worthless at shooting down aircraft and the S-400 would be worthless at shooting down satellites.
The S-300/400 systems can engage highly maneuverable, highly fast and very small targets at any altitude. Both systems can be quickly deployed within minutes (crucial). Both systems can manage a battlefield by tracking anywhere from 100-300 targets, both systems have a data-link network which makes it very difficult to kill or jam.
In any the anti satellite weapons take meticulous planning which could last days, weeks or even months before the right window of opportunity is there which includes whether and vector timing--not to mention orbital launches are often delayed for a number of technical reasons.
The MKV is a highly specialized weapond, it would not be able to engage, for instance, low level targets.
How is that when even the Russian Air Force is still testing them. Moreover, from what I have read China was interested in engines and avionics and not purchasing