Creating great landscape photos require patience as photographers may have to return to the same spot over extended periods waiting for the right moment. They pay close attention to the cloud formation, weather, contrast, direction of shadow and many other things. It is not practical to take the same approach when doing massive corporate group photos since there are many people involved and it's unlikely that you can get everyone to agree to take a photo at the same spot till you get the perfect shot. In such a situation, the retoucher can use retouching to enhance the image.
We took the following image from an aerial work platform for UBS at The Promontory at Marina Bay, Singapore to celebrate its 50th anniversary in Asia:
As you can see, several issues needed rectifying. Some of which include the lighting, sky, patchy grass, random people in the background and dustbins. These are mostly out of the photographer's control. Nevertheless, the photographer/retoucher can correct it with retouching. Do note that this is a time-intensive task. Every effort should be made by all involved to make adjustments at the scene to reduce the amount of work in post.