Ser Trant was a cowardly, no honor having knight out of his element in a new continent focusing on getting his nut off. Walder Frey was in his home surrounded by his people. I’m not buying that after a few months of training Arya has the skills and know-how to pull something of that caliber off. (and understand I loooooove Arya. She has been and still remains one of if not my favorite character of the series)

Maybe if she just killed Frey alone, I could believe it. Or if she killed the sons alone I wouldn’t think twice. Not killed the sons, baked them into a pie, fed it to Walder, killed Walder. Too much too soon.