Seriously, I hope that there is a legitimate competition for the starting spot (for EVERY starting spot, hopefully). If Fitz's ankle is 100%, I suspect he will win the competition, but he has to get better at the deep throws. From everything I have read about Moorhead, we can expect to see both QBs play, and sometimes see both of them on the field, although Moorhead will probably hold on to those packages until the big games.
As for Mayden, I have already read interviews in which he says he expects to redshirt and learn the offense for a year. But, since Mayden is left handed, I'm betting we could see a 2019 package that looks like this: