When Chuck and Jimmy worked together, they were able to get tons of Sandpiper money in 1 case. A McGill McGill firm would have been as powerful as Saul Goodman's power :
Better Call Saul' recap: 'You say potato, I say spoliation' - The Washington Post
Better Call Saul' Season 6, Episode 6 Recap: The Smell Test - The New York Times
Who is Rand Casimiro in Better Call Saul season 6?