You can't qualify an absolute 'need' with 'if they continue to blow away games'. That's not something we can or should assume will continue happening. We shouldn't assume they're going to go back to their 17-9 or whatever start either, safest bet is somewhere in the middle (or cumulative performance), which has put them in the giant mess of teams within 1 game of a playoff spot. None of those other teams have made any substantial moves either. I can totally buy an argument for jumping the market, but big picture this is just how these things usually work.
As for the kids, as curious as I am about them, where do they go? Davis and Canario are already on the 40 man, so I assume you're talking Caissie? BJ Murray and his .646 OPS don't inspire a lot of confidence, I don't know if Matt Shaw's 114 wRC at AA warrants jumping to Wrigley. So you have three outfielders/first basemen trying to get consistent ABs among Busch (136 wRC last 30), Suzuki (130 wRC last 30), Happ (118 wRC last 30), Bellinger (107 wRC last 30), PCA (gross offensively but still a positive producer and also very much a 'kid'), Tauchman (bad in his last 30 but very obviously in the circle of trust)....take DH PAs from Morel? Wisdom's 2 starts a week? Hoerner has been bad, the catchers have been historically bad, the bullpen has been awful. There aren't any clear fixes for those in Iowa.