Neris, Benoit and Ramos all have enough velocity, problem is they don't have the movement on their FB or the deception that makes it hard to hit.
ML hitters have been self-selected to hit straight FBs over the plate up to 97-98 MPH (see World Series).
So command and movement are just as important as velocity.
The real problem is command, Neris can't consistently throw his splitter, Ramos has a nice curve but it's easier to pick up off a FB than a slider or changeup. Benoit struggles commanding all his pitches so far.
I think Eickhoff may have arm trouble, he was really laboring the last two starts. In the long run, needs to master a change to go with the curve.
Hellickson is what he is, a 6 inning #3 starter who should give you 30 starts and a 3.5-4.0 ERA/FIP.
Velasquez is learning on the job, really needed a full season (26 starts) in AAA ball or more before coming up.
Nola is merely a matter of health, he's added velocity but the elbow/back?
Eflin is a work in progress, has a great FB (nice movement, good velocity) which he's still mastering and the off-speed stuff is a work in progress, but all the tools are there.
Pivetta really needs to go back to AAA where he can refine his stuff without pressure, he has the power FB but isn't quite ready.
Thompson is lost in the bullpen, doesn't get the velocity uptick.
However, next year they should have 5 young starters, and a deep AAA rotation.