Howard hit .251, .881 OPS, yet only 1.8 WAR (BR) in 2008. His fielding and baserunning was that bad.
Santana has 0.8 WAR which projects to about 1.4 WAR.
Point is simply that you can add guys like Howard in free agency pretty easily.
Rollins (5.5) had a big WAR season primarily based on defense, which also helped Victorino (4.4).
MM would be a nice addition, but there are numerous ways to skin this cat.
If Crawford is a plus fielding SS, he just has to get his OPS > .750.
If Kingery can regain his hitting touch and move to 2B, he could be a major player.
Alfaro has unlimited potential on both defense and offense, worth waiting a few years to develop.
Hoskins will eventually move to 1B, if he settles in offensively, he can be far more valuable than Howard.
And so on, some of this improvement needs to be internal, some from strategic acquisitions.
It is nice to have stars, but you can also dominate with a lineup with no weaknesses - i.e. that keeps the pressure on every inning. So if you can't land/develop the outlier, you develop solid starters and use FA to fill a hole or two (and keep Polanco).