I don't think anyone on here has said the very good GM's like AA are perfect. AA has made some mistakes or questionable decisions in Atlanta as well. Nothing wrong in questioning him. Yeah AA miscalculated the value of Contraras and trading him away was a mistake.
As for your comment about Atlanta's pitching depth, it's incorrect.
Darius Vines was pretty solid in the bigs last season and did pitch well in his first start this season. Solid minor league track record as well and is only 25. I mean he's nothing special but not a bad depth option if you need him for a couple of starts.
Braves also have Bryce Elder who is getting called up for tonight and likely now will take Strider's spot in the rotation on a full time basis. Elder is only 24 and was an All-Star last season and finished 12-4 with a 3.81 ERA in his 31 starts. Not bad for your 6th starter and he has proven he could pitch a full season out of the rotation.
Other options the Braves have: Huascar Ynoa, Dylan Dodd, AJ Smith-Shawver, and Allan Winans. As well, their top pick in the 2023 draft Hurston Waldrep could be MLB ready in July if he dominates in AAA.
So overall in total, I count 7 total viable possible SP options after their top 5 of Strider, Fried, Sale, Morton and Lopez.