the japanese hg/ss list.txt won't work for the english hg/ss. use a japanese rom, edit the sprites, save your work.
Then extract the two files from the japanese rom found here: (use nitro explorer)
a/0/8/1
a/1/7/9
(I'm unsure which has all the overworld sprites you're looking for, so I just use both files. if anyone knows which is the proper one for overworld sprites, feel free to correct me on that.)
and reinsert them into the english rom. Then you should have your edited overworlds.