I've been preaching this for a couple years - as the average velocity increases, hitters are self-selected for swings geared to hitting high velocity fastballs. So command of your FB and mastering at least two secondary pitches is more important than additional velocity once you get up to about an average of 91-92, t95 or so. Velocity becomes more valuable in terms of separation in the speed of different pitches (except when you get to 97+, but few starting pitchers can sustain that kind of velocity, half their pitches will be under 95 even if they average 95). Throwing less fastballs will also protect your pitchers and lead to fewer injuries.
This is actually what Klentak is preaching, command and pitchability over velocity, and plate discipline for hitters.
Tirado throws 100+ but lacks command and may never make it.
Sanchez throws 100 with command, but needs to develop two secondary pitches to ever be a top starting pitcher.
You don't have to power a fastball because of physics - if you have a quick stroke and center the barrel on the ball, the velocity of the fastball will add to the exit speed of the batted ball. So it's more important to focus on pitches you can barrel (don't swing at FBs above the chest or breaking balls low and away) than taking big, aggressive cuts at the ball - that's what turned Judge from Cozens to the current superstar.
That's why Stairs is trying to teach Franco to stop trying to hit balls so hard, perfect that quick, compact stroke, don't open up trying to pull balls, take outside pitches to RF and trust your raw power. The toughest teams we've played are teams like the Nats, with good hitters who don't swing at balls, forcing pitchers to throw strikes and jumping on mistakes. Most pitchers struggle with command, how many "outside" FBs do you see drift over the center of the plate? Nola is our best pitcher, and when he's "on" it's when he can throw his two seamer over the outer edge of the plate, the 4 seamer shoulder high, and drop a curve knee high for a strike. And when he perfects his changeup he'll become a #1 starter. Because the key isn't blowing the ball by people (ask PIvetta how well that works for 6 innings) but keeping batters offbalance.