So I'm looking at LA. They, of course, don't have Greinke behind Kershaw anymore. They have Kazmir. And "I throw 88, but from the left side" Wood. Anderson. Recovering Ryu. Newbie Maeda. 72 year old Chase Utley and his patella at second. Crawford, Pederson and Puig in the OF. A bunch of crap in a bullpen that historically underperforms.
Not saying they suck, exactly, but there are cracks in the mortar there, too.
At SF, same thing. 3-4-5 are Samardzija, 38 year old Peavy and - is he done? - Cain. The bullpen is unimpressive, Casilla as closer. OF starts Blanco and Pagan.
Are those clubs really light years ahead of the D-Backs? I sure don't think so.
Just going down the position list between those clubs:
Catcher: Giants>Dodgers>Dbacks. Posey is a future Hall of Famer. He wins. Grandal is no slouch, though, so he gets the second nod, especially with Barnes to spell him. Castillo is a distant third. Tuffy Gosewich has an awesome name, though.
First base: Dbacks>Dodgers>Giants. Goldy is a consistent MVP talent, so he wins here. Gonzalez is still a consistent above-average player, but you can't beat Goldy here. Belt is pretty good as well. Those guys are similar value.
2B: Giants>Dodgers>Dbacks. Full year of Joe Panik wins here in my eyes. Howie Kendrick/Kike Hernandez/Chase Utley isn't bad either. Jean Segura/Chris Owings/Phil Gosselin doesn't win here. Maybe Brandon Drury gets called up and does well.
SS: Giants>Dodgers>Dbacks. Crawford is really good, and Seager is a potential superstar. I give the edge to the Giants because of Crawford's track record of success, though Seager could very well be Rookie of the Year. Ahmed, while great with the glove, just can't compete; Segura doesn't even come close to their level.
3B: Dodgers>Giants>Dbacks. Turner has been well above average for the past 2 years, so he gets my nod here. Could see an argument for Duffy being the better of the 2 for sure, though; he would've been Rookie of the Year in a regular year without all the crazy Correas and Bryants of the world. Jake Lamb was barely an average regular this year. Plenty of room for improvement, and of course Drury could come up and be good, but much less of a chance than the others being good.
LF: Dbacks>Dodgers>Giants. Close win for Dbacks here; I think Peralta is slightly better than the Ethier/Crawford combo that will play for the Dodgers, but not by much. The Pagan/Blanco/whoever else in SF will be a distant third here.
CF: Dbacks>Dodgers>Giants. Clear win for Pollock here. Pederson and Span could have similar value with vastly different skillsets; I like Pederson, personally, but could go either way.
RF: Dodgers>Giants>Dbacks. Puig has phenomenal ability if he's healthy. Pence has been a very solid contributor for quite a while. Tomas is poop.
SP: Giants>Dodgers>Dbacks. This one is really hard for me to judge, but this is my thought process: the Giants have a fantastic 3-headed snake in Bumgarner/Cueto/Samardzija (who's stuff will play up in that big ass ballpark in SF). Cain/Heston/Peavy isn't the greatest 4/5 combo, but it's pretty average. They get the slight edge for me. Kershaw is the best starter in MLB; he's damn near as valuable as most teams 1 and 2 starters combined. Kazmir is pretty good in his own right, Ryu was very good before his injury, Maeda has good potential, Anderson had a solid year and is another year removed from injury, and McCarthy could very well come back strong; Wood is also a good piece for them. Finally, the Dbacks got much better at the top of the rotation with Greinke/Miller, but Corbin/de la Rosa/Ray isn't exactly great. Could be they play up, but overall I'd take the Dodgers rotation there.
RP: Dbacks=Dodgers=Giants. I'll be honest, I'm not super familiar with their bullpens, but to me it looks pretty close. Dbacks have Ziegler/Clippard/Hudson at the back end, though Clippard in that home stadium probably won't end well. Jansen is as good a closer as you'll find. Casilla is ok, but the rest of their bullpen is pretty meh. They're all pretty meh. Can't really pick one.
Bench: Dodgers>Dbacks>Giants. Having Kike Hernandez, Barnes, Trayce Thompson, etc. gives the Dodgers the clear win for me. Dbacks have Drury and Owings in the wings, as well as Socrates Brito, so they take 2nd. Giants have a bunch of guys whose names I don't know but will probably have a Rookie of the Year candidate because of black magic; I name them third out of spite.
So, in conclusion, the Dbacks "win" at plenty of positions; the difference is most of the positions they don't win are distant thirds, and even the ones they do win are pretty close outside of Goldy. They could for sure make a run if things break their way, I just don't think they're good at enough positions by a big enough margin to do so.