So I would create an empty file and copy and paste the script into it and call it "validation.fix" and and then make it executable and store it somwhere.
Then following your guide instead of manually changing md5sums I could run the script.
I would not need to have the script in the directory I was working in?
Actually that script would make it harder to fix the validation as you have to download the tarball from the AUR page, extract it, copy the script to the directory, run the script, run makepkg as root and then install as root (pacman -U filename.tar.xz.gz). It is much easier to just md5sum the source file as yaourt asks if you want to edit the PKGBUILD anyway.

This issue is a rare occurrence that only happens in a great while
Normaly I guess. Not if you are trying to install Windowmaker Dock Apps from AUR. Never seen so many failures and orphans since I was at school

That is because the package maintainers have not updated the packages for the new version of WM as the development had stopped a few years ago before they started it back up. So in other words, the packages do not work as they are not built against the new version of WindowMaker.