Sorry it’s been so long for a reply.
WC’s and headhunters are explained on pages 7 and 8 of the rules and have a moral of D6 (sometimes D8 for headhunters).
As noted on p7 and 8 WC’s flee from zombies, although not clear in the rules I always assume that WC’s will always move to cover if fired upon closest if moral role made – IE more successes than failures in the group, or closest in the direction of the result of the scatter role on p7 as panic makes you do the strangest things. You could even go as far as to role individual moral and cause the group to scatter which is more realistic in my mind?
Headhunters as noted on page 8 operate like other military units but with lower moral dice, so you follow the moral rules for professionals on page 39 of the rules.
Hope this helps,