By Andrew Gould The San Francisco 49ers pulled off a rare NFL blockbuster by trading for Christian McCaffrey. While the flashy upgrade immediately improves San Francisco’s offense, not everyone loves the move. ESPN’s Seth Walder graded the deal a C-minus, asserting that the 49ers will likely wish they didn’t give the Carolina Panthers so much draft capital for the 26-year-old running back. “The most likely outcome here is the 49ers will end up regretting this choice,” Walder said. The 49ers gave their second, third, and fourth-round picks in 2023 and a 2024 fifth. They only own two picks (a th…