I think it would be fine either way but I feel a slight preference for the way it is in the screenshot.
My reason is that it lets me scan across from left to right to see what is different / similar in the different environments. That would be more difficult if the lists were on top of each other instead of side-by-side. (Think about drawing a line through the hotkeys which are all the same on a row. You can do it without crossing other hotkeys in the current layout, but transpose the layout and you would have to go through things.)
Maybe I'm strange for wanting to compare the different environments, though? I guess most people only care about one or two of them most of the time.
Having said that, perhaps it's more important to optimize the layout based on which axis you expect to be larger in general, since the pages dimensions aren't square.