A senior lawyer leaving a large firm is no longer much of a story. A senior lawyer leaving to question whether the firm needs its familiar hierarchy is something else. On October 14, Leon E. Johnson, a San Francisco transactional partner formerly at Goodwin Procter and Kirkland & Ellis, emerged as the leader of Omnilex Partners, a new American practice linked to the Swiss legal technology business Omnilex AI. The move is a small test of a large proposition: that a law firm mi