Who should I choose as the leader between these two and how will the storylines differ?

Honestly I have no clue what difference it will make. It will for sure and maybe for a future cg scene that you will get it if you let him be the leader. As for now, I suggest that you should have a save file right before collecting the votes, that way in future IF you need to let the other become the leader, you can do it easily. As for me, I let rasmus win

Wow, thanks for the answer. I chose Einar as the leader because I think he has the most leadership qualities.