several models argue a strategy and every trade before anything is placed, and only on paper.
Models debate to consensus before a decision is final, and the whole routine runs in paper mode, against a shadow book, until that book earns the switch.
Parallel voting among models. Rejected because a vote averages away the argument, and the argument is the only thing worth keeping.

Paper mode. No real order has been placed; the shadow book is the only ledger, and the live switch stays off until the book earns the turn.