Here is a composite I created using images borrowed from Steelblue and Foster and Partners. Since I am not affiliated with either entity, and images I've posted previously on Skyscraperpage have been used by others for various purposes at various websites; out of respect for Steelblue, and Foster and Partners, I have watermarked the image. I am posting this for discussion purposes only.
The height of this version of 50 Main at 1066 feet is correct for this perspective view, so it appears slightly taller. Even in elevation view, Salesforce Tower and 50 Main would appear almost identical. Please note again that design of 50 Main could very well change from what is portrayed here. I also didn't update 77 Beale/200 Mission - the shorter tower just next door to the left.