I'm not sure if this is the right place to put this. I'm developing a python script to create xfe icon themes from KDE/GNOME icon themes. It works like this:
1) It first search for the freedesktop icon naming spec equivalent
2) If step 1 fails, it search for a KDE equivalent
3) If step 2 fails, it search for a GNOME equivalent
4) If no icon if found then it creates a symbolic link to the xfe_theme icon
5) If the size of the icon found is not the expected the script resizes the found icon and create a new image in the new theme folder. In the rest of cases the script only creates symbolic links to the original icon and so you need it installed (I could modify the script to make it create copies instead of symbolic links).
In the script I make some assumptions when the icon doesn't have the size in its name (icon_AxB):
1) If the xfe_theme icon name starts with "big" or ends with "big.png" its size is 32.
2) If the xfe_theme icon name starts with "mini" its size is 16.
3) If not 1 or 2, then the size is 16 by default.
The resulting theme is in general good looking, but the mapping is incomplete yet (about 200 icons). To create a theme modify the NOMBRE_TEMA variable with the name of the icon theme you want adapt (oxygen, Faenza, gnome, etc). The theme generated is stored in /home/user/.config/xfe/icons/theme_name.
Licence is LGPL v3. Comments/additions are welcome.