The human vs. human approach may take more feelings into account, things like who had the most family waiting back on Earth, who would boost morale, etc. But with human vs. nature, it’s purely about survival which causes us to make very different decisions than we probably think we’re even capable of prior to being presented with the choice.
Daniel Dae Kim mentions in the exclusive clip above that Stowaway is a story that examines human vs. nature more than human vs. human.
It’s an extremely interesting point, and a valid one, as the film really explores these characters and the decisions they make based on the likelihood of their own survival.