I thought that this was established by having two sets of difficulties on the two different screens. I agree that it may lead to some confusion of why their are two different levels of difficulties, but I believe that this will raise enough questions for the players to realize that their are two separate difficulty settings and probably lead to a lot of forum questions. I believe this should at least be in the FAQ on the forum for new gamers.
In fact, maybe us vets should make a FAQ for these new players. I would start it, but I really cannot fathom any real questions that I don't think is clear from context (unfortunate side effect of my field).