This Dak vs. Trevor Lawrence debate is starting among Cowboys fans. It is being presented as "If you have the chance, do you take Trevor Lawrence with a top 5 pick, or do you stick with Dak Prescott?"
The answer is: you do both.
Lawrence just turned 21. Dak is 27. When Dak is 32 or 33. at the end of whatever contract is being contemplated, Lawrence will be 25/26. There is enough of an age difference to make it worth the value.
If Lawrence comes in and quickly turns into an elite quarterback, then Dak becomes valuable trade bait. If Lawrence busts, we still have Dak.
People will create reasons that this won't be a thing, probably talking about "splitting the locker room" and so forth. But both Troy and Roger had to fight for their spot with genuine competition (or at least the perception of such).