解釋 Preemptive work

preemptive work = work done to stop some actions that will be harmful to yourself
預防性工作/措施以防止有損害的事發生

原句的 and hard bargaining 在句中是解不通的，因為用上 and 就必順接上句子前部份，但 and hard bargaining 接不上句中任何部份。

將句子修改如下
Thanks to a combination of preemptive work and hard bargaining, Dimon's crew simply managed risk better than its rivals.
全靠一連串預防措施及討價還價，Dimon那組人員在處理危機上比對手出色得多。

Thanks to a combination of *preemptive work*-Dimon's crew simply managed risk better than its rivals and hard bargaining.

**=預先的準備工夫