Answer:
This is likely due to the fact that both cultures highly valued warriors and their contributions to society. Therefore, it makes sense that they would have special places in the afterlife reserved for those who died while fighting. This would allow these individuals to continue serving their community in some capacity, even after death.
Additionally, it is worth noting that both the Aztec and Norse cultures were quite violent and had a history of conflict. This may have also played a role in why they both placed such a high importance on warriors and their role in the afterlife.