In Brave, it is said that DunBroch has a had history with Vikings, Vikings being one of the invaders that forced the four clans to unite. Fans like to imagine the Hooligan Tribe being one of the tribes that aided in the invasion.
Much like North, fans often compare Stoick to Elinor's husband Fergus. They are both large, bearded, muscular warriors, incredibly stubborn, leaders to their respective people and father-figures (or in Stoick and Fergus' case, actual fathers) to their respective members of the Big Four. Unlike Fergus however, Stoick bears his burdens without his wife, and while he has help, is forced to deligate and calculate on his own, making him a more practical leader and man.
Fans often like to portray Stoick and Elinor as bitter allies, willing to make peace for the sake of their people and growing closer as friends through the bond their children share. In rarer cases, they grow close as lovers, possibly as a contender as a betrothed when they were younger or for other reasons.