Oh, this one will be fun!
I hate it, so much. Whenever I see the "Brosatru" t-shirts on Facebook chest-pounding with the whole "I'm going to Valhalla!" BS, I face-desk all the way to China.
To be a warrior is to fight in wars - militia, soldiers, etc. It is not battling disease, or fighting for rights, or other some such metaphorical "battle." It is to be one of war.
Valhalla is the Hall of the Slain, not "Viking Heaven." Even should one die in battle (if they are Heathen,) Valhalla is not guaranteed. Freyja chooses the first half of the slain to reside with her in Sessrumnir, and then Odin receives the other half to reside in Valhalla. The Golden Hall itself is not a tavern where barfights rage eternal. The Einherjar - the honored dead - do not fight every day and drink every night. Valhalla's 540 doors lead to the barrows of those warriors; the Golden Hall is a place of peace and rest, where the Einherjar gather to feast, sing, and relax from a life of war.
Most of those Heathen who die will reside in Hel, resting peacefully for eternity.
Though, as I personally believe, the afterlife is not one destination; it is all of the Nav'. As my soul (my spirit and essence after death) will reside in Hel, it will also be in the Christian "heaven" with my parents, and anywhere else that holds relevance; cognizant and personal, not a clone or facsimile. And so with all souls.