You haven’t shared enough data to tell whether there was a financial payoff for the firm or not. The consultant is a fixed cost to the firm, so saving consultant time doesn’t necessarily translate directly to higher margins nor revenue per worker.

Are the consultants delivering more billable hours per person now?

All sorts of reasons why the answer to that may be: no.

The firm charges a fixed fee to the client. The client doesn't see anything different from what they got before, the firm increased their gross margin overnight.