Here's how my thought process has evolved regarding Darunia:
First, I thought, "They should have Darunia. They'll probably have Darunia."
Next, I thought, "Then again, they have a raging hard-on for TP. Maybe Darbus or Dangoro, who are also mighty Goron warriors."
Then I thought, "Bu Valga's in the game, repping Volvagia. It has to be Darunia."
And that's where I'm now at -- Valga/Valvagia suggests to me that if any Goron makes it, it'll be Darunia.
Ya know, I never made that connection, but Darunia chasin' down Valga makes perfect sense as far as a plot motivator goes. Let's say he gets a side story like Agitha and Midna, who's his co-op partner? Saria? Ruto? Maybe he can rock the fastball special with Groose and the Groosinator.