Wieters: 168 AB
Jones: 207 AB
Matusz: 54.2 IP
Wiggy: 170 AB
Simon: 12.1 IP
Ohman: 16.2 IP
Your math doesn't compute here. Wieters = Wiggy, but "overachievers" Ohman and Simon together have half the innings of Matusz. And I'm not sure you can call Simon with his 1.54 WHIP an overachiever; the 6 out of 7 saves is good but quite a small sample size.
Um, are you really saying that "actual baseball" doesn't include the role of the manager? As fans we can evaluate the players but not decision making from the dugout? Sure, it's your personal choice, whatever. But why is the manager off limits? Granted, there's no statistical "proof" of blame on the manager. But as Bill James alluded in that PDF article ("Underestimating the Fog") about "lineup protection" and other sabre-myths, absence of evidence does not equal evidence of absence. It seems that in sticking up for Trembley you are buying into the fallacy that James points out which says "that the absence of proof is proof" (i.e., of DT's freedom from responsibility here). Your point about "we're playing about what we should expect" has some merit if you assume and accept that nearly everyone on the field is underperforming. The question remains, why are they all underperforming (again)? To answer this question should imply looking at all the factors, not first shutting some in a closet and then looking at the rest.