Franchise mode with current rosters .

[Catch2271]

What’s the best way or what way can I start a new franchise with the current rosters AND have the current draft class and picks ?? 
I know I can sim this past season and go through the entire schedule and sim the wins for each team every week all the way  to the Super Bowl with the current draft class loaded but how can I get all the FA moves in and will the draft picks be the same or somewhat close ?  Will I have  to select every team at the beginning of my Franchise like be the coach of every team and make their corresponding FA moves and trades ? Seems like tons of work but was curious as if this will work ?  Yeah been thinking way too much on this one lol. Hoping someone out there can simplify it for me .