I had Pharmacist Mutual as a practicing pharmacist, and they were willing to work against the chains when necessary. It's not that pricey, and they do a good job with representation in the Southwest when you need it. The only reason why I don't use them anymore is that my insurance has to be a PLI now because of my job and Pharmacists Mutual does not underwrite a government one with protection for administrative leave. I use FEDS for that and disability supplemental (for the risk eventuality that the VA will drive me clinically insane) for $400 a year which $200 is directly paid back to me from OPM and the other $200 goes on the 2% deductions, and I have had to make a claim before which was absolutely painless which basically paid for itself for a lifetime when I collected from two weeks of administrative leave.
For pharmacists in practice in the federal government, you should be careful about purchasing (I think it goes so far as you should not) pharmacist liability insurance as most policies specifically exclude government action in any cases that you could be involved in. You should consider PLI if you are a supervisor or you have contracting authority. And both sets of insurance is completely worthless in a uniformed situation, there's specific PLI geared for those employees in the same way ATC and LEO personnel are covered.