Ultimately it's up-to you what resolution you use to generate your encodes....
Some people prefer to generate cropped encodes with "non-square" pixel (ie: anamorphic) resolutions, such as: 720x432. Others prefer to generate cropped encodes with "square" pixel resolutions, such as: 1024x432.
When the video decoding chip-sets within hardware players were limited to support a maximum resolution of 720x576 (total 414,720) pixels, you had to generate anamorphic encodes if you wanted the image pixel area of your encode to match that of the source.
Today however, the video decoding chip-sets within hardware players are able to support a maximum resolution of 1920x1088 (total 2,088,960) pixels. So you're perfectly able to generate encodes at say, 1024x432 (total 442,368) pixels
So maybe encoding to a anamorphic size doesn't matter all that much anymore with latest hardware players/ computers? The media tank I use seems to be able to handle the high resolutions that he talks about, so I wouldn't need a anamorphic encoding....