This included some pretty physical action sequences, so it’s understandable that Bateman wanted to make sure Pelphrey was conserving energy for whenever possible, making sure he was ready to go for the bigger scenes down the stretch.
Jason Bateman probably knew that while filming Tom Pelphrey jumping in the lake could be neat, every scene needs multiple takes, and Ozark Season 3 needed the actor for other physically demanding (and clothed) scenes.
If cutting back on that lake scene made the difference in getting Ben to tackle that landscaper with that much more brutal force, it was well worth it.