Spoiler alert if you haven't seen season 3 of Ozark, the following will spoil things.

After Del was dispatched, Helen showed up in Lake of the Ozarks. She was clearly established within the Navarro cartel, and she offered tangible value in US, representing the Byrds.

Yet, after she is dispatched, Navarro promotes the Byrds...but they aren't lawyers. Wouldn't replacing her with another lawyer have been helpful? Especially once they started negotiating with federal agents, why didn't Navarro replace Helen with another lawyer?