I just can't come to a conclusion reading from the sources. I see the competition was (in my understanding) between Aishah bint Abu Bakr, Safiyya bint Huyaiy, Maria Qibtiyya and Juweirya.
For instance, it has been narrated that Aishah mentioned a kind of jealous remark of the other three in terms of beauty. But the Prophet always put Aishah as his most beautiful wife? I do not understand.
Please give some narrations to support your views, Jazak Allah.