Could a better GM than Getz gotten back better prospects/players than what Getz did in his deals (Bummer trade, Fletcher, Vargas, etc.)?
Yes, end of story. Cali is sweeping a broad brush over everything, while there are still ways the team could have been improved.
None of those trades involved a lot of money in which JR was a bottleneck. These bad trades were all on Getz’s poor assessment of players.