Gauntlet Genie

Open the Squads menu, then navigate to Squad Management. In that page you should see a "Gauntlet Genie" button at the top. Click that button and it will open up a menu with some options.

From here, you can select the squad you want to copy tactics and formation from, choose to not use loan players or make it so the substitutes are low rated.

The strategy dropdown decides whether the builder will try to make 3 balanced squads or put most of the best players in the first squad.

You can then generate the squads, wait while it creates them, and see the output. Once you are happy, click apply and your new squads will be generated for you with unique names.