Great Barcelona and Real madrid in different Pot hopely they will be meet again in Elclassico match. The Pot 1 is most group of death.
If I am not mistaken, teams from the same league can't go to the same group.
So we won't see RM vs Barce or Chelsea vs ManUtd in the group stage.
I am not sure what you mean by "Pot 1 is group of death", as each team in the pot 1 will be in a different group.