Captain Cadaver said:Assuming they're both at least as strong as they were in their final fight, they should each be capable of winning individually. Hagoromo only stated that Madara was approaching his power, whereas Kurama stated Rikudo Susano'o Sausageke was equal to the Rikudo Sennin.
Hagoromo = Peak Naruto/Sasuke > Rikudo Madara. Putting both of them against him is overkill.