As a thought experiment, take it to the extreme. Let's say Lewis was #1 on the Braves board and required full slot money, while Anderson was #10 on their board and only required $1 to sign. In that scenario, the 100% correct choice is to sign Anderson for $1.
The actual truth obviously lies somewhere between those extremes. There is nothing wrong with paying less for the #10 guy on your board so you have cash to sign Wentz and Muller. That is a perfectly acceptable course of action, and is likely what the Braves did.
It is also completely understandable that they then spun it like they got "the guy they wanted".
Yeah, no ****, but enough with acting like the Braves took the BPA at #3 with no regard to signing cost.