Checks totalOrderCount against the investor orders received and moves the model order to Processing. Every investor
order is then re-validated in the background and the model order moves to Received, or to Rejected or Failed with a
reason code. The outcome is sent as an OmnibusModelOrderCreated, OmnibusModelOrderRejected, or OmnibusModelOrderFailed
webhook, and can also be read by polling the model order. A count mismatch leaves the model order in Draft.