Isn't this literally the same format as African qualifying?
I thought I remember when Bob coached Egypt that they won a group and then got drawn for a head to head vs another team in a win or die match, which was Ghana or Ivory Coast?
Looks like last time around it works like we are suggesting. There were home-and-home in the earlier rounds, no different than how CONCACAF used to do it, but the matches that actually determine who goes were all group play with the group winner advancing to the WC:
https://en.wikipedia.org/wiki/2018_FIFA_World_Cup_qualification_(CAF)
So at least one bad match didn't eliminate your chances of qualifying.