In every sport everything is possible including in football,but I would never call this group "a death group".Spain and Portugal are much more powerful teams then Morocco and Iran and anything then clear win from Spain&Portugal would be a great surprise.
I know Morocco have at least one big star Medhi Benatia and he is know as one of best defenders in Africa playing in Juventus.They are ranked as 40 on Fifa list and they did not participated in World Cup in last 20 years.
Iran is ranked as 32 on Fifa list,and they have Carlos Queiroz as coach-he is very well known Portuguese coach.They star is Sardar Azmoun who is their main striker,he score 11 goals in qualifications.