Extra 400MHz isn't going to solve your Warzone issues. The game itself / and or Geforce driver version you're on is most likely the problem.
Say if you were to overclock ram and is successful by loosening timings and perhaps adding a tad more voltage for stability if needed, you wouldn't get the results you're after.
Fast ram helps, that's the bottom line but it's more important for Ryzen than Intel. Differences between 3200 and 3600 on your 9900k system would be negligible.