Just another thought which occurred to me: it seems to me not always easy do determine straightforward which is the sharpest lens, as test results sometimes differ. An example: the widely hailed Zeiss 21mm lens is tested at DxO according to their measuring unit with 14mpx, which is really just mediocre, many zoom lenses do better. Is this lens sharp or not? I have an 18mm Zeiss lens which receives on DxO even one point less than the 21mm, 13mpx, but I like this little lens very much: its results seem to me at least quite sharp, excellent contrast, no flare, lots of keepers, use it very frequently. The praised Nikon 14-24 zoom gets 17mpx which is good but not all tha much either: the really cheap Samyang 14mm gets 20mpx. (all on a d800)
Should one go only by the numbers? I personally think lenses have other qualities, too, and not only bokeh. Contrast matters, and image which is subjectively pleasing (for my analogue large format work I have some brass lenses from the last century, uncoated, soft contrast, but very nuanced tonal scale and quite sharp). That is to say: tests give you, as far as I can see, an idea in which ballpark a lens is, but there is more.