Zombie management is sometimes difficult and I can’t ever tell which zombies are fresh and which are old. Dismissing ALL zombies to make fresh ones can sometimes be impractical.
I think one of the following would solve this problem easily;
*A spell; It would refresh the duration of all active zombies to their maximum. (It could cost Zombie Capsules).
*An attribute; when at 8 zombies It would cause any action that would cause a zombie to spawn to instead refresh the duration of the oldest zombie to it’s maximum.