I agree with you. A code reviewer from the same company, even with different models or efforts, shares the same blind spots. To review my code, I use a different company; if I code with Claude (usually Sonnet 5.5-medium), Codex reviews it, and vice versa. I get much better code this way. But more importantly, I always tell the reviewer to build its own test-scenario ledger and refute the coder's claim that it is done. And the verdict is shared with the coder, but the coder cannot reject it.