It depends on your camera-angle really. When it is at eye-sight, you can position the key a lot higher. I often like to position the key from above (you might need some fancy equipment for this though, or be creative with the tripods), most of the times you get red of the shadow like this. You can use filters as well to make the light softer, but these don't get rid of the shadows, they only make them less visible. So, in my opinion this isn't a solution. You can also use a few, to get the best of both methods. And just like Denny said, flags are a very effective way of getting rid of your shadows and control your light more. But it really depends on how close the character is to the wall. I'm not really sure if filling the wall with other lights is the best solution. Controlling the light is better than putting more lights in there.