Does it surprise you?
Look at their offense. Sure they have top tier players in Tatis and Machado (Manny isn't the right player for San Diego I think though nut he still is a very good player) but aside from them, what other offensive talent do they have? Their second best hitter last year was Jake Cronenworth. Unless you massively overrate Wil Myers and Eric Hosmer, there's not a ton of talent there. WHen you think of the Braves you immediately go, oh yeah, Freeman, Acuna, Albies. That's a rock solid trio. And that's roughly what San Diego has with Tatis, Machado, and Cronenworth (though I don't know if I think he can keep playing at a high level since he didn't break into the bigs until he was 26, but maybe he's a Ben Zobrist type who made a big change to his swing and approach) but the Braves then followed that up with Riley and Swanson, both much better performers than Grisham and Pham.