Why does the Gemara bring proofs to the Man d'Amar that Or is day - take a break with proofs to the other Man d'Amar and go back to the first ?
Shalom Rav,
To answer the Kashya why the Gemara continues to bring proofs after the first Sh'ma Minah, the Rashba explains that the proofs were not all learnt in the same Beis-Hamidrash. They were learned in various Batei-Midrash and Ravina and Rav Ashi collected them all and arranged them as part of Shas. That being the case, it may well be that the order in which the proofs appear is the order in which Ravina and R. Ashi heard them, irrespective of which opinion they come to prove.
Be'Virchas Kol Tuv,
Eliezer Chrysler