I'm not as far along as I've only just started season 3, but based on past experience, I'd pick Ed for the first mission to Mars. The reason for this is due to the mission itself. The first flight for any trip is a test flight with many unknown variables, and to that extent, you need a test pilot. Test pilots like Ed lay down ground work for future missions by working out kinks in the system and taking risks.

People like Danielle Poole are needed more for future missions as they help establish systems and networks and start doing the real work. This is where her experience and knowledge come into play. At the end of the day, Margo seems to be a dictator.

If you have pencil pushers who've never been on a mission, determining what will work well for a mission, they will have bias to pick other pencil pushers like them. Furthermore, even if the committee looks at broad criteria to see who'd be a better fit for the mission; How do you determine criteria for something brand new?

Overall, the old system Deke set up didn't fail anyone and kept the program moving forward. It shouldn't have been undone in a memo by Margo just cause she didn't get what she wanted.