Are you serious? Those five guys, awful as you think they are, have 4 of our 5 hits tonight. On top of that Pedroia is on the DL, Marrero is way better than Pablo on defense and Pablo doesn't hit lefties well. Travis hits lefties way better than Moreland.
Vazquez would no doubt have hit better than Leon, but my guess is Leon got the nod because he's a better defensive catcher.
So my question back to you is, what the hell are Betts, HanRam, and JBJ doing out there? No hits among them plus JBJ looked awful running into Betts who was the right guy to make the play on the single to right center.