I doubt any GG stock zombie character models are rigged any different than another.
*?< Oooops. I guess I was wrong. >!* Some behave as if they are. Zombies are NOT
my thing!
The .FPE file contains a list of the animations you can assign for various actions (to move for example). But these steps might get you near the task, but it doesn't complete the task. The scripts are the same, ((different names but contain the same instructions.)) I notice the speed (100 vs 300) is set differently in each of them. I guess nobody answered because you probably actually have to modify animations. But first try various animation sequences that you want @ .FPE file to see if any fit close enough for your needs.
You probably already know GG has to be restarted after an .FPE modification.
Female Zombie Office-
anim0 = 2552,2603;idle
anim1 = 300,318 ;move <<<<<----------
anim2 = 2981,3034;bite
anim3 = 2984,2990;hurt
Headband Zombie;
anim0 = 210,234 ;idle
anim1 = 533,603 ;move <<<<<----------
anim2 = 683,722 ;bite
anim3 = 686,692 ;hurt