It's probably hard to sustain the consumption of a Divine Servant, and signing a contract wouldn't be a good choice for either party.
So only Akai Hinako is suitable. On the surface, her persona is that of a Mage dedicated to the Master. Recommending her to sign a contract with Ishtar not only effectively increases our bargaining chips, but also makes my previous statements more reasonable.
After all, if Akai Hinako never manages to get a Servant, it would be hard for Gu Mo to show complete trust in her, this "visitor from Chaldea." The previous claim that she was the last Mage to save humanity, Chaldea being humanity's last hope, would also appear somewhat suspicious.
Just like Fujimaru Ritsuka, if she didn't have any Servants from start to finish, only herself, who would believe that this Master on their own could accomplish anything? How could anyone believe she had the capability to save the world? That's obviously impossible.
