Almost no architecture could survive an Apollo-13 type accident
The explosion of the oxygen tank in Apollo-13's service module gutted the service module. That sort of accident would wreck almost any single spacecraft architecture. As everyone knows, the astronauts survived because they used the LM as a lifeboat and the command module was undamaged. Perhaps the lesson of Apollo-13 is to travel to Mars with two spacecraft in close formation but physically unconnected. Each spacecraft would have sufficient resources for an emergency return of the entire crew from both spacecraft. The expense of such an approach probably does not justify the improvement in safety.
Gary