No one should expect a fourth outfielder to be an All-Star
Well the phrase is used these days like it’s an official specialty. We have had “utility player” used for many years. “4th outfielder” is a newer term. But language leads to new narratives. And soon enough it’s a specialty.
And yet, with such small benches, specialized players on the bench are that last thing we need. We need flexibility from everyone on the bench and from as many of the starters as possible. The solution to huge bullpens, necessitated by short starts, is either larger active rosters, more flexibility with activating and deactivating players for games (like they do in the nfl) or just having less games.
I understand your point, and not here to say Pham is a bad 4th outfielder. But the use of historical examples was inaccurate, in both specific examples and premise. Floyd went into the 2006 season as the starting LF. McRae was the 1999 Starting CF. In 1986, Mookie was injured in spring training in a rundown drill. He and Dykstra were a platoon. George Foster was the starter in LF.
But more so, the premise. The term “ 4th outfielder”did not exist. There were starters, often more than 8 due to platoons, and there were bench players. The benches were far deeper, because starting pitchers pitched far more innings and bullpens were far smaller. In 1999, behind McRae on the bench were outfielders Jermaine Allensworth, Mike Kinkade, and Roger Cedeno. Part of a long bench that also included Luis Lopez, Matt Franco and Todd Pratt.
If you need to compare the choice of Pham as a fourth outfielder, you should use contemporary examples. Who are the other 4th outfielders in baseball today, and how does Pham compare? Then you should look at how many starts would be expected from a 4th outfielder on a team with starting outfielders Marte and Canha who even if healthy will each rest at least once in every 5 games. And in a league with a DH, unlike the example years you presented.