For every star who is an instant success, there are 2-3 players who develop over time.
I've watched these players all year, and you can see they have the potential to be more than bench players.
Heck, Guthrie keeps surprising me (and probably the Phillies brass) by both hitting but also showing more plate discipline than I would have expected - to go with his defense at various positions.
There's a big difference between a bench player you rarely play and playing someonebecause he can fill in more than capably at various positions - and the Phillies seem to be developing some of the later, Maton, Guthrie, Vierling - they're what they tried to make Kingery to be.
The only kid who isn't positive WAR is Vierling, mostly a combination of plate struggles and playing out of position in CF, but he's hitting better and Marsh allows him to play corner OF.
Stott needs to hit better, but his second half improvement and a BABIP of .269 suggests there's lots of upside. He was rushed and it shows, but he's settled in and his defense is better than expected
But Maton is the kid I'd bet on to breakout, his short but powerful stroke and plate discipline suggest that with enough PA he could be a very good hitter.