If you have expectations of Ronaldo type role, then he can't be on the left.
Ronaldo plays LW loves to cut in and make it rain with that right foot. Same would apply with Bale with the left foot
But Ronaldo doesn't spend all his time solely on the left wing, you will often find him drifting centrally and sometimes even floating wide right to try and influence the game. Players as good as Bale, Ronaldo and others will always look for space to have the maximum influence on the game.