An adjuster is applying a policy to a set of facts. Most claim disputes come down to whose description of the facts was written down first and in more detail.
A dwelling limit set when the policy was written and never revisited is the most common form of under-insurance, and the clause that enforces it is easy to miss.
A large company's standard agreement is written to protect the large company. Most of it is negotiable, and knowing which parts to push on is the skill.