#zero experience in politics and yet her opinion is given the same weight as any longstanding council members

[berk-council-official]

Since Hiccup and Astrid are betrothed. Is she part of the council now? As part of her chieftess training. Does she sit with the Hoffersons or Haddocks?

No, she's not part of the council. The chief's spouse usually steps up to help them, but this is such a small village that that's not necessary. Knowing her, she probably will, though. She's also not getting any training, because her marriage is a relationship like any other, not a job. Valka wasn't Stoick's right hand when she was alive, because she despised dragons, for instance. That was Gobber.

What usually happens is that the chief's spouse steps in as right hand, but Gobber does it fine and he hasn't trained for it, just grew up with Stoick.

Finally, the group isn't made up of representatives of the major clans, it's made up of representatives of the major jobs. The traders, and fishers, and farmers, and whatnot, which deal directly with whether the tribe will last through winter. Tribes that seat their clans usually just have family rivalries as discussions, not anything actually important. Hiccup Haddock currently sits as both heir and head of the dragon academy, but the latter seat will likely go to Fishlegs once they're not impulsive teenagers anymore.