Yeah, they're definitely worrying. We don't really know anything about any of their acting talents, and the female Dornish costume design has been a bit weak, especially compared to how great their designs have been for the men. But my understanding from reviews is that even people who got the screeners have only really seen a scene or two of them, so I don't think anyone knows enough to say for sure. And even if they're bad, I don't think they really become a jump the shark moment unless they're really really bad. I mean, the show survived the SciFi Original Series of Dany in Qarth, so I think it can survive this ok. I do hope they maybe redo the costumes or something when they go to KL next season.
Also, isn't the woman playing Nym literally a Star Wars extra?
And man, my friend who hasn't read was asking me the other day if Yara was ever coming back, and I had to tell him I didn't know because she's so far off the books, and got to explaining to him how cool she's supposed to be in the books, and it depressed me all over again. Also, he brought up how creepy her intro in season 2 was, and it made me realize that for all the hate we give the dogs, that scene was fucked up nearly as badly. 100% less funny and 100% more gross and creepy.