A parallel to the lots selecting the goats - birds! Including Sotah. But also if one choose bird korbanot because of the expense. And then what happens to the birds... which seems to have different parameters from the goats of Yom Kippur, in any case. Also, with regard to the goats - the kohen gadol ties the red string on the head of the goat going to Azazel. He positions the goats, and then utters his confession. The Gemara's focus shifts to the wool used for the red string. Including the connection to the parah adumah. Including confusion, apparently, by the Amoraim (and us too), and the need to compare Yom Kippur to the birds and the parah adumah.