I can't really blame the writers for deviating from the source material so heavily. They have a year to create the entire show and are forced by constraints specific to television (budget, actors, time to shoot, location etc).

GRRM has had 5 years since his last book to come out (16 years since the last truly great ASOIAF book IMO) and is constrained only by his own personal difficulties in writing the stories, and were still left with nothing.

I think a story of this magnitude is simply very difficult to write and that sometimes you have to take shortcuts with characters. I would have loved to see more Osha but I can kind of understand why the story doesn't really have room for. What I have no patience for is the terrible dialogue we got in Dorne last season.

Also I loved all the siblings that reunited this episode. It felt like such a big payoff to see some Starks FINALLY in the same room together.