My biggest issue is the opinion of “the Giants would be doing themselves a disservice by not signing Harper.” By signing Harper alone, the Giants don’t automatically become a contender. None of the free agent signings this off-season guarantee success or failure. The Giants would need a lot more to go right for them to do better than last season.
I know that seems like a pretty obvious statement, but it’s still right on. You can’t have Harper and then a lineup full of guys hitting .250, plus Posey hitting .300. Unless of course the pitching staff is lights out, which is always a remote possibility. Again, Harper (alone) does not make or break this organization.
That being said, the presence of Harper takes pressure off the rest of the lineup. Now instead of guys trying to hit for the fences and playing Hero Ball, you can have a more cohesive lineup. Having a power bat also takes care of the 3rd-4th lineup spots, so you don’t have to worry about changing the lineup every day to see who fits where.
There are tangible benefits to having a Bryce Harper in your lineup, but those benefits don’t always equal to great success. Just look at the Nationals and where they’ve gone; playoff appearances in 2012, 2014, 2016 and 2017 and not a pennant or championship to answer with. Harper’s best playoff appearance was in the 2014 NLDS, but the Nationals simply got out-managed and out-lucked. There is no certainty for team success with Harper in the lineup.