Umm, not that it matters really ..
Because it is Sam and Dean so .. Sam is Dean’s Sam.That is all that actually matters in the end.
But if there was supposed to any Collette parallel – They just confirmed it is Sam who is Dean’s collette.
The one who SEES the real him, despite everything - the one who just gets him - Despite all the wrongs he is doing because of the Mark - It is Sam who is believing in Dean and Dean’s goodness. The one having utter faith in Dean even when he is literally sitting on his knees waiting to die … Sam is the one who sees the good in Dean underneath it all - Sam is the one who is giving acceptance and forgiveness… Sam is the one telling him to STOP. And if it means that he has to do it by killing Sam then so be it … It is Sam who is telling him he can not know how to love even if he forgets ..that he can love again, be good again, be himself again…even if it is at the cost of Sam’s life. Dean has to be stopped, and Sam is ready to pay the price -And still only asking for one thing -To try and remember what it was like to be himself, to be the good guy who loved. In exchange for that, he is willingly surrendering himself to his brother.
Sam is the one who is ready to forgive, Sam forgives Dean even before Dean asks for forgiveness.And Dean asks, and Sam just does.Dean sees the forgiveness and love and still that faith in Sam’s eyes, no fear,no terror, only regret and sadness, but love …