The Pagoda roof was not chosen for the W113 because of more visibility but because of its safety features.
Interesting assessment. Note however that "chosen for safety" and "designed for safety" may be two different things. US Patent #3,169,793 of which Barenyi is listed as inventor, and Bracq also listed, have the second paragraph reading:
...since they permit the passengers to enter the vehicle much more easily and also permit the top to be more easily loaded with baggage...
Nothing is mentioned about safety or strength or visibility for that matter. Just saying! Perhaps the safety due to strength was just a byproduct of the design for egress which then led to the choice. The patent is the patent; the choice was made over other designs. Those with my Pagoda book have seen Bracq sketches of the Pagoda with a more conventional roofline. Those without the book here's the page. These are all Bracq sketches made during the W113 development; dates are provided in the text.