Fun note: for me personally (after a metric ton of failed RP attempts in different formats) the 1-1-1-1-1 scenario is actually a bit easier for me to handle. The alternative is making sure five people all understand the same scene at the same time in the same way, which to be frank drives me nuts sometimes. :D

This way each character's actions can have repercussions that affect the other characters, like a ripple effect. (Like Izzy sending in the calvary.) No character is ignored or left behind. And you can always move toward another character's location if it gets lonely. ;D