One proposed tactic has been that either cops need to hold individual "malpractice" insurance (like doctors) or that settlements need to come out of the union retirement fund.
https://www.npr.org/2019/04/12/712606977/how-the-insurance-i...
The insurance idea is stupid. It will just end up being bought by the union, removing the individual incentive component, and added as a line item the next time pay negotiations come up.
They don't need to, but that's not how insurance is sold. Unions collectively buy and negotiate benefits for their members. And a requirement from the union would be, no doubt, universal coverage and pricing.