> ensuring that only those with the right expertise remain

How will this ensure waning/gaining expertise is accurately represented/fostered? Wouldn't you rather attract a steady-stream of experts indefinitely?

In practice, anyone with sufficient funds can become a broker. The pseudo-random selection process means that the probability of Broker A being chosen to audit or inspect an item is positive. If Broker A accepts and validates an item they are unfamiliar with, regardless of its actual validity, the likelihood of a dispute arising increases. Since Broker A lacks knowledge about the item, proving their case becomes challenging, potentially resulting in financial losses. Over time, this situation should lead to a pool of brokers with expertise. Consequently, the system is likely to attract a continuous stream of experts, as expertise will prove itself financially advantageous.