JeffK said:
Jon Arryn didn't want to be King enough to fight for it. Hence, House Arryn is not a main player in the game of thrones. They're supporting cast.
And House Arryn SUPPORTED House Baratheon in the rebellion. They never sought the crown themselves. Once again, supporting cast.
Should GRRM change this in the next book (if we ever see it), your thematic argument will have more merit. As it stands, I still don't see the reasoning behind their being a house vying for the throne, which is what the game is all about. It's not about which houses are "major" houses - it's about which ones are trying to rule the realm.
Then why would the Night's Watch have so many cards and be a playable build? If this game actually had to be about the "Game of Thrones", then there's no reason for the NW to be in it at all (arguably).
Going back to the Magic comparison, yes they have five colors, but again, because of the blending of mana types, there's actually way more decktypes so to speak, but again, only a couple which are tournament worthy but I understand what you were trying to say. Yes Game of Thrones can do it with six houses, but they could also do it with five, and they could also do it with seven, so what? The weird thing is that "Wouldn't it be cool to have a new house?" totally qualifies for me as a valid reason to make it. Anything that looks awesome, provided it's balanced, will make me want to buy it. I will want to see if a new house suits my playstyle better, and I will want to try out new tech against the environment. I would also want to take on the role of a different group of characters and see what other houses get against new mechanics. I really like the idea of faction loyalty, and playing neutral Arryns under a plain blank shield just doesn't interest me. I want to get stoked about the team that I pick, get a custom playmat, color coordinated sleeves, and bring them to tournaments no matter how good or bad their current builds are. It's one of the reasons I never play NW or Wildlings, and never will put any of them in a deck. But again, that's just me.
I will add though, upon reflecting, that one of the primary reasons the addition of a new house appeals so much, is probably because although I only recently got into the LCG, I had played the CCG since Ice and Fire. I've been seeing a lot of the same themes, decktypes, and card evolution replicated or replicating in the LCG and I'm looking for something more drastic than changing the distribution methods. I'm just saying I think the game could do with some fresh mechanics, under a fresh banner, and further, that the game should do with it.