Moon, kudos for this breakdown. A lot of research, much appreciated, showing virtually any contending Red Sox team the past half-century plus had at least two solid starting pitchers.
I'd add that a bonafide 1-2 punch in pennant stretch-runs can also evolve, and supersede season totals for games started.
For example, the '67 Impossible Dream team's #2 man became Jose Santiago, who went unbeaten in his last six decisions and wound up leading the majors with a .750 winning percentage. Santiago was good enough to start World Series Games 1 and 4 vs. Bob Gibson, then made the All-Star team the next season before elbow injuries basically ended his career.
The other instance was obviously 1972, when Tiant's comeback not only made him Boston's main man, but also the majors ERA king. His last days in a Sox uniform were at the end of '78, when any fan who lived through it would still pick Looie and Eck as their 1-2 starters...
We also know Eovaldi and Price evolved into the top two guys in Cora's multi-role staff plan in the '18 postseason, as both starters and relievers. Remember, Price carried the stigma as a playoff failure, and had been surpassed as staff ace, first by Porcello (in his Cy season), then by Sale. But Price found a new pitch/delivery in a Houston bullpen, warming up late in a close ALCS game... then won two World Series starts vs. LA.
But what a mound mess in '05, after the Sox let Pedro and Lowe go. They won 95 because their offense scored 5.62 runs per game, but good pitching wiped out crapshooting in the postseason. That October the White Sox went 11-1 with a rock solid starting four. Intuitive Red Sox fans sensed it was already over when Game 1 starter Matt Clement hit his first batter (by the end, it was confirmed: Chicago 14, Boston 2).