Yes that's right it becomes murkier when insurance is bought via a broker on their "block" policy where the terms are harder to establish. What is the difference in a landlord insuring with an insurer with a block policy and they, or a one off client, buying it from a broker- both spread loss/profit across the policy.
It boils down to given a clear claims history and assessment of current risks, what can be shown to be sensible terms and premium.
Based on the information posted, I offer my thoughts.Any action you then take is your liability. While commending individual effort, there is no substitute for a thorough review of documents and facts by paid for professional advisers