Rosenthal's story today talked about how most teams will likely cut payroll. The Phillies aren't really in a position to do that. But even if they just come back with the same payroll, assuming JT returns, they will have to choose between 2 of Didi, a starter or a high-end reliever (or two mid-level relievers).
I think they'd have to non-tender VV to really be able to afford anyone "mid-rotation," caliber, while a #4 might not be better than Vince. If you're confident in Eflin, that's probably okay. But the other thing Rosenthal's article talks about is how hard it is to glean anything from this season's sample. In a normal season Eflin might have dipped at some point. Conversely, maybe Howard would have gotten better.
If money's no object I still sign someone who slots ahead of Eflin. In a perfect world you'd just hope Howard equals him and you have two really good #3 caliber starters, but can't really expect that in the short-term.