Try this first. However, in my case I saw no difference and moved on.
That said, if you want to try you just need to use a series of hg pull -r REV commands into a new clone. Something like this:
hg init my_reordered_clone
cd my_reordered_clone
hg pull -r d84b1 ../un_reordered_clone
hg pull -r 6d269 ../un_reordered_clone
hg pull -r bb9e4 ../un_reordered_clone
If your workflow only merges branch heads, you can get the desired revision order by sorting revsets by date. This you can do with the following command:
hg log -r 'sort(0:tip, date)' --template '{rev}\n'
Or with interactive rebase AKA HistEdit extension by reordering the lines in the text file
hg log -r 'sort(all(), -date)'
Sadly, no graph love