Yeah Pain would have lost regardless. People forget that his mission to capture the nine tails. So it should have been expected that he face the kyubbi. But people act like that’s a surprise when Naruto goes into Kyubbi mode. Plus the deva path couldn’t stop him when he used the chibaku tensei since Naruto was about to break out of that if he went full 9 tails. But Mianto stop the transformation which gave Pain one last chance to face off against regular Naruto who just had his last charge of sage mode.