You don't do a fantasy draft at the start of your franchise. There is a 'fantasy draft' option for filling the roster on your created team in the team setup. You chose 'fantasy draft' instead of cupcake, air-it-out, etc... This option allows you to put any players you want on the roster of your created team. This is why you write down the 50 players you move onto the replaced team before you create your new team. So you can make sure that their rosters are identical. This way when you replace them to start a franchise there are no duplicate or missing players.