What is really comes down to is whether Klentak revamped the organization and it'll bear fruit the next few years, or it was just lip service. The story about Simmons having to figure out the flaws in his swing instead of coaches pointing it out and correcting it doesn't garner optimism.
You don't have to have prospects arrive in droves, but you do need to find some Sixto/Altuve types who play far above expectations if you're drafting in the middle of the pack and have a limited LA allocation. And you have to be able to fill out the roster with later pick college pitchers turned functional RP, trades for guys other teams have underestimated, and coaches who can fix flaws and turn some marginal prospects into players.
Spending $20-30M on the bullpen, and having to spend $20M for SP depth just isn't tenable in this cap environment, especially if you resign JT, pay Harper, Wheeler, Nota, Sergura, et al. The Phillies have to find some cheap help.
Guys like Welch and Victorino were key to the last successful team, low cost starters for years, along with all the hits on draft picks over a six year period.