In Salvy's defense, he's been brutally unlucky, even for an old immobile catcher. He's underperforming his xWOBA by 100 points, .250 wOBA vs .350 xWOBA. Maikel Garcia was always an exit velo darling, and had pedigree as a top 100 prospect who plays good defense all over the field.
The Royals formula is similar to last season's. They have a superstar in Bobby Witt Jr., a secondary good hitter, and just elite SPs. Bubic emerged this season as an ace to go along with Ragans, Wacha and Lugo (who's been only okay thus far) round out a rock solid top 4 and Lorenzen has been good for them as well. They also added Erceg late last season and Carlos Estevez over the offseason to solidify the back end of their BP and it's doing wonders.
Honestly kind of a model mid/small market team. Once Witt broke out they supplemented him via trade and shrewd signings. These smaller market teams can be players in free agency too!