You can add other M3 models for some of the efficiency benchmarks. The headline still holds true when comparing to M3 Pro models (though the exact efficiency diff depends quite a bit on the exact M3 Pro model/core count).
It looks like they don't have benchmark results for Cinebench 2024 for some older models, so they're only shown when you switch to Cinebench R23. The Witcher 3 benchmark, for example, does show M3 Pro numbers by default.