The surprise decision by star dealmaker Scott Barshay to move his practice from Cravath, Swaine & Moore to Paul, Weiss, Rifkind, Wharton & Garrison is likely to shake up both firms’ financial results and M&A standings this year, according to legal industry experts. But the move also casts new doubts on the viability of Cravath’s pure lockstep model of compensation, an outlier in a market where rivals have a freer hand to invest in top talent.

By bringing on Barshay, a Cravath lifer, Paul Weiss immediately boosts its M&A practice, which has trailed that of Cravath. Paul Weiss ranked 20th in global announced deals on the Bloomberg M&A advisory rankings last year, compared with Cravath’s second-place ranking. A significant number of clients are expected to follow Barshay, who has been named Paul Weiss’ first global head of M&A.