"Parenthetically, three of the top ten lenses ever tested by DxO Labs are Sony G or Sony/Zeiss, so, while Leica glass is almost always superb, it’s not as if what Sony offers is cropped liver."
Be aware of the potential fallacy in this "top ten" list. It is based on the DxOMark Score, which in turn is related to resolution of the camera used for the test. While DxO has tested various lenses on Sony and Nikon 36mp bodies, they apparently have yet to test any lenses on a 50mp Canon 5DS or 5DSR. Canon lenses are pretty much ruled out from being on the current "top ten" list by virtue of the Canon lenses all having been tested on lower resolution bodies like the 5D3 & 5D2. If they test Leica SL lenses, Leica will have the same problem as the camera is 24mp.
No doubt the Sony and Sony/Zeiss lenses are excellent, but they might not comprise three of the top ten if not for this quirk of DxO ranking.