The weaponry doesn't matter so much. That's not what makes a GoT game.
What matters most is the Houses. Houses should be the focus.
What matters secondmost is intrigue and social conflict being deceptively dangerous. More dangerous than physical combat. Which also must produce a rather high fatality rate.
Fourthly, magic must always, always, always come with a nigh unbearable price. To the point that I would consider that all magic attempts might get an automatic Despair.
Look at Green Ronin's SIFRP game. It has its flaws, no doubt. But they absolutely nailed what makes GoT feel like GoT.
GoT isn't heroic fantasy. It's horrific fantasy. Every player should go into every session expecting severed limbs, unwinnable choices, and death. So much death. In fact, a successful character in GoT is the one whose death wasn't meaningless, who advanced the station and fortune of his House as he died.