1) The US intelligence community, esp. the CIA, had predicted back in the mid 1980's that Russia will first counter stealth by using VHF (30 MHz to 300 MHz). So this is very old news!

2) In the kill chain of shooting down an invading plane/missile, you need not only to detect but also to guide the missile to its target! VHF detection radar is limited by their range and effective scanning envelope. Guidance and targeting radars by Russia have been unreliable against US 5th generation aircraft thus far and assuming no other employed counter measures being active. That's why the Russian S300 & S400 must be used simultaneously to cover each other deficiencies. The developing S500 is another beast.

The reality ...

1) If you get lucky and scan the limited right envelope of the sky, you can detect

2) Can you effectively & reliably shoot down invading aircrafts/missiles employing decoys and counter measures?

3) Russian and Chinese counter measures are ? That's why Chinese DF-21 missiles (carrier killer) hope to overcome its limitation by shear quantities ... just like its fishing fleet strategy in the SCS!