this
Being able to win Rus vs Rus or Ger vs Ger doesn't just make someone the "best" player for that faction, strengths in all matchups must be considered.
You are right. We need all the matchups possible to figure out how strong a player is. Also what S73v0 said. If we can test it in the beta and it turns out be be somehow bad then it can stil be removed later. But i stil dont see why it should be bad tbh.