The funny thing is that simply not calling this "RA9-WAR" would make the post feel less insecure to a lot of people.
"advanced stats think an average pitcher would have a 5.33 ERA against the same teams. Because Ray has a 2.71 ERA, that means over 159 IP, he's allowed 46 runs less than the average pitcher. Now, because it's using RA instead of ERA, it's actually 43 runs, but it's a minimal difference.
For a "barstool conversation" (IRL not a reference to random sports website), there's a ton of really easy ways to reframe RA/9 WAR especially if you're willing to sacrifice 10% of the stat's accuracy to carve out the more wonky aspects of it (park & opponent factors and RA/ERA [when difference is minimal])