I haven't tried this yet in practice, but it seems like a good improvement.
This will be the most common choice for anyone who disables notebook tabs.
If they disable notebook tabs, why does it matter? Isn't the menu only shown for people who keep tabs enabled?
This also groups the commands closing multiple documents separately from the other commands. Closing multiple documents is a more drastic action so should be grouped separately.
This doesn't really give a good reason for the ordering, for example an alternative layout that puts the _least_ drastic action first but maintains grouping of "close" related items together would be:
``` Open in New Window ---- Close Close Other Documents Close Documents to the Right (Close Documents to the Left) (Close Documents in Same Folder) (Close Documents in Other Folders) Close All ```