Can: The Dodgers are very, very deep and very experienced, and that matters
We can parse the stats as much as we want, but the reality is that even a cursory look at the team’s rosters reveals a pretty big discrepancy in depth. The Dodgers have some of the best players in all of baseball at their positions in Freeman, Betts, and Will Smith as well as All-Star-caliber guys who are underperforming like Muncy (aside from the dingers), Chris Taylor, and JD Martinez.
Over on the pitching staff, Clayton Kershaw is past his prime certainly but is still good for 6-7 of excellence every night, and the Dodgers should be getting back Urías before too long (he finished top-three in the Cy Young race last year).
With the Diamondbacks, Gallen and Carroll have been amazing and they have gotten real production from guys like Geraldo Perdomo, Ketel Marte, Christian Walker, Lourdes Gurriel Jr., Merrill Kelly, and Andrew Chafin. However, a lot of those guys don’t have the same track records that the Dodgers’ guys do, although Ketel Marte has been productive in MLB for a good while.
Finally, most of the Dodgers' players are extremely battle-tested and have multiple tight division races and deep playoff runs under their belts. For the last several years, LA has had a target on them as one of the best teams in the league and they have largely lived up to the billing each year despite some shortcomings in specific playoff series. Arizona doesn’t have that and it's unclear if they'll be able to perform when they are trying to seal the deal.
One note here, though, is that that last point could go either way. While we have seen plenty of young, inexperienced teams wilt under the pressure of a tight division race, the opposite can also happen. The Diamondbacks may play so loose and with nothing to lose that they simply may not notice or know any better. Teams with the level of talent that Arizona has who also lay it all out there with nothing to lose can be very, very dangerous. Either way, this division race is setting up to be one for the ages.