Adding your property manager as an additional insured means they will be listed on your insurance policy as a named insured.

Insurance is awful.

I have home owners insurance should i buy another landlords policy as well?

Many insurance companies do not allow adding a landlord as additional insured.  

I knew the fire insurance would be CA Fair Plan.  

., We were over a decade without insurance, and when I refinanced and insurance was needed, I had no trouble getting insurance in place.  

Any recommendations for Umbrella insurance providers for each partner to cover any liability?

Insurance right now is wild, so I'd get a solid broker on your team - I'd be happy to share my contact if that would help.Also, aren't most of the existing insurances shared on the OMs for the properties? 

Quote from @Nicholas Dillon: I read somewhere that you can request to have your mortgage insurance dropped once your Loan to Value reaches 80%.

Can you suggest an insurance company and contacts for our rental houses?