You can talk to these dudes and take their temperature.
The Jazz might not be contenders this upcoming season, but they should be by the following year or the one after that, all of which Jrue should still be relevant. Try to elevate the years were Lauri and Walker are still cheap.
Go look at any contender, there are often large age gaps on the roster. Usually among starting rotations 2-3 will be around the same age +/- 3 years, you will have 1 guy who is 25 or younger, and 1-2 very veteran players. That's how you build a championship roster, with a max of age groups.