They have different layouts, when Sasha has to prepare 3+ quads it's a heavy burden. We now know about the injury for Rostelecom this year. Russian Nationals last year is the main competition she bombed, and Anna has messed up before too (although not for a long time). Also both have been nervous on the 3Lz-3Lo this year. Sasha preparing 1 type of quad repeated twice went clean first time despite not having perfect trainings either.
Kamila, I guess she "looks" nervous. But then she did what she has never done before, at the most difficult competition. She messed up the 3A and that was nerves so fair.
And Aliona never fell on a 3A once last year despite it being a new element. We remember Anna and Sasha falling on their quads when they started to jump them, it's understandable, but what Aliona did is unreal. We even kept seeing her fall and having bad practices! But never in competition.