I am unsure weather it is possible to change the playermodel's bodygroups. I checked the whole menu that the gamemode provides (F1), but didn't find such thing.
Those seperated playermodel addons (Enhanced playermodel addons) dont work here, because they break the gamemode and keep the playermodels on zombies after the player dies and turns into a zombie (that does quite break the scenario and informs me of script errors).

I'd like to be corrected if there is such an option located in the menu. If it isn't then Id like to keep this as a suggestion that would open dozen more playermodel combinations in the gamemode.

I'd also like to point out that I'm worried weather the autor of this addon will see this, because of no recent activity in the comment section of the addon, but I still want to try. Thanks for reading/considering