You NEVER let all-pro players in their prime leave. This team should have absolutely no salary cap problems. They paid for the past spending now with years of much stricter frugality (despite a couple of overpays in hindsight in Dez and Crawford although those are still 2 good players), and now Romo will be off the books in another year. Our starting QB is on a rookie contract. We have signed very few free agents for a couple of years. All this talk about having trouble signing Lawrence, Irving, Hitchens, and Martin is silly IMO. Transition or Franchise for a year or two if you have to (Lawrence makes sense, because he has had PED suspension and injury issues in past, and only 1 monster year of production - although I like him). They can give solid signing bonuses, and smaller early year salaries, and stretch out contract - no problems.
This team can't afford to lose consistent, pro-bowl players that don't have trouble off the field........This guys should be dominant for years yet - why would we ever give that up for the unknown?