Once you reach Commander Level 40, you will gain access to multiple slots for Saved Squads.

When you create a team in any mode, you can choose to save that composition and use it across any game mode (Campaign, Challenges, Arena, Blitz, Raids, etc.) for multiple sets of teams.

You won't have to recreate your team compositions since they will persist across all game modes. Save your favorite Squads and use them across Arena, Blitz, Campaigns, Events, and Raids!