Cannot override RedisCache by FileCache in local

I’m in an yii2 development project.

I have RedisCache in config main.php components like this:

   'cache' => [


        'class' => 'yii\redis\Cache',


        'redis' => [


            'hostname' => '127.0.0.1',


            'port' => 6379,


            'database' => 0,


        ]


    ],

But it just is used for QA server, in local I want use FileCache as default of Yii so I overrided Cache config in main-local.php

    'cache' => [


        'class' => 'yii\caching\FileCache',


    ],

=> Cannot override with ArrayHelper::merge because it still have property ‘redis’ in FileCache!! Should I replace ArrayHelper::merge by array_merge to fix this problem? But then I need to copy all config to main-local.php then just override which needed??

Which is the better?