Yes, "sample size" matters. Nobody is installing Travis Shaw in Cooperstown or forgetting that Brock Holt doesn't wear well over the course of the marathon that is the baseball season. But if the 'eye test' tells you that they give you the best chance to WIN TODAY, that's what matters. So, if Pablo Sandoval and Rusney Castillo sit, they sit...and get paid.
Sports is a meritocracy, but embedded within are fragile egos and "that's not how we do it here" attitudes of "professionals". Veterans who see other veterans displaced can become petulant. "You don't lose your job to injury." But you do lose your job when your conditioning prevents you from fielding a ground ball or running the bases or when our judgment on your potential gets disproven.
The Red Sox and manager John Farrell skate on thin ice. Baseball fans have short memories for success and longer ones for disappointment.
Baseball players most often get paid for what they've accomplished in the past, but fans respond to what you're doing now. Should the fan who pays a king's ransom accept players who don't care about conditioning or performance once they've been paid.
A high payroll guarantees nothing as we've seen the Kansas City Royal and even Houston prove last season. Players and management need to understand that winning might be optional for some teams but not the big market teams. And if winning isn't your priority or your emphasis, then you don't deserve OUR money. Money can't play.