Remember when I said you were going to come up with nonsense?
This is that nonsense.
In the real world:
Terran players are not worse on average: ✓, of course not.
The game is precisely even at all skill levels: ¯\_(ツ)_/¯, but I think so
Terran players have drastically lower MMR: ╳, except when viewed as the mean average without accounting for population disparity
In the hypothetical proposition:
Terran players are not worse on average: ✓
The game is precisely even at all skill levels: ✓
Terran players have drastically lower MMR: ╳, since then things aren’t even.