@lse123 try an keep a single source of truth with your users table. From my memory, cakephp and Laravel are quite similar in table names, but it would make sense to modify Laravel models so they use the cakephp tables. You can can specify the table if its not default by
protected $table = 'my_odd_table_name';
You'll need to customize Laravel Authentication to use the same hashing for passwords and secret key.
I'd then create additional functionality in Laravel to match the cakephp functionality, and then retire the cakephp admin.
Once that's complete, you can rename the Laravel tables, FKs and modify the front end to use the Laravel table names + new columns on your joins.
As you build you new admin, be sure to cover its functionality with tests, as that will be essential when you modify the tables and retire your cakephp app.