millions of galleries, now what?

so, I got this giant html file of galleries but I want them in a different order.
for example, now it shows as

50 galleries of site 1 from sponsor a
50 galleries of site 2 from sponsor a
& so on...
then 50 galleries of site 1 from sponsor b, etc, etc


what I want is;
1 gallery for site 1 from sponsor a
1 gallery for site 1from sponsor b
etc all the way til I need to get to site#2 /etc.. basically spread them out so they're not all gouped together like when I downloaded them

what can I do if I don't want to code by hand