The Pitchers will have to come off the books.
The Cubs have to decide on the core. Is Arrieta core? I think he is because he will outlast Lester physically, and Lackey. His stuff is better than Hendricks and I would trust him more going forward.
Rizzo
Bryant
Schwarber
Russell
Arrieta
Baez
Hendricks
Contreras
Davis...
Heyward by contract
is the "core" order I would select and build around as best you can with funds available. As Ommy said, next year "core" and dynasty don't matter. Just don't make Heyward type moves that jeopardize the future core. He is a problem, because they picked him into the core, but he shouldn't be. Can he be shipped? Next year it doesn't matter, but Lester/Lackey/Heyward/Zobrist are going to have to come off the books as young core guys get contracts eventually. We are probably talking about problems arising in the seocnd half of a dynasty's decade.
I can't recall a team this good being assembled so young with this many possibilities ahead. But if you look at the history of championships, I would not get rid of the middle defense, Baez and Russell. Just ride that. Center fielders can be found, or Heyward. The middle defense is amazing. That middle defense is a hallmark of several past championship level teams.
Also...having 2 big bats like Ramirez and Ortiz. But 3 is a magic elevator. So Schwarber/Bryant/Rizzo have to stay, which should in a salary cap league effect pitching just a little, but basically Epstein is going to be dealing from those core 5 players and probably Arrieta/Hendricks/Davis
Contreras would be kept on most teams, and might be a 6th core fielder. Plus Heyward. But see.....you just can't have 9 core fielders, 4 core starters, and a full bullpen, can you?
Lets revisit in 2 years, the only thing that matter now is the question of Arrieta, and if you are given an opportunity by someone to move Heyward you do it. Or Schwarber if you are given the entire world by an AL team and put him where he belongs in baseball.
But you would think that can wait until the team salary is unmanagable, not projected 8 under.