Mookie is not exactly Cal Ripken Jr.., but I take him for availability and versatility over Trout, which I think are two things that are still under-rated in this game.
Just a hare-brained theory, and I'm certainly not going to research it any further
, but if you had to average in the WAR of the bench player's that had to replace Trout's spot in the lineup with the player's who had to replace Mookie, I'd wager their WAR totals would be closer together then they are...and they're NOT THAT far apart, considering Trouts career started 3 years before Mookie.