Lisa Monaco, the Deputy U.S. Attorney General previously worked as a partner at the law firm O'Melveny & Myers LLP. At O'Melveny & Myers, Monaco represented Humana–the fifth largest U.S. health insurance company–according to her financial disclosures. Notably, O'Melveny & Myers also successfully defended United Health in a suit brought by United health group insured patients earlier this year.

Health "insurance" company, not provider.

The number three at DOJ, Acting Associate AG Benjamin Mizer, also represented healthcare and pharmaceutical giant Sanofi-Aventis, among others firms.

While not an insurance company, Sanofi-Aventis (now Sanofi) was provably corrupt and predatory on multiple occasions in multiple countries and was/is VERY much part of the same problem as United Health and the rest of the health insurance leech industry.

Finally, #4 at DOJ, Solicitor General Elizabeth Prolegar, reported Lumos Pharma, Syneos Health, and Amgen, as former clients on her disclosure.

Syneos have been sued for firing people who take family leave that they're legally entitled to and Amgen pleaded guilty to guilty to improper marketing that put patients at risk

In conclusion: while you're technically right that only one of them worked for INSURANCE companies, they all worked for health sector companies that were and are part of the problem, so it's a distinction without importance in this case.