Ensemble characters. Characters that say "yeah" semi-resignedly a lot. Some characters will die on you. It's constructed like The Expanse, but the plot is definitely going to go very differently.

The Carryx suddenly swoop in to the world of Anjiin, where humanity lives but where their origin is lost to time. The Carryx quickly conquer humans, killing 1 out of every 8. Dafyd Alkhor's group is transported across the universe to a glorified prison planet where the team is given the task of making themselves useful to the Carryx. If they do not, humanity will be obliterated. Lots of intra-group conflict. Lots of conflict with other prisoner species. Lots of perceived conflict with the Carryx, who mostly ignore them until they've proven themselves useful.

Do they collaborate and maybe live to fight the Carryx another day, or go out in a blaze of glory since it's likely humanity is going to die anyway so why not go down fighting? Climax is a giant trolley problem. Don't forget that trolley problems are largely constructed as thought exercises, and here it's a thought exercise to move the plot along. In other words, don't get too attached to the philosophy. Whichever way they go it's just a story.