What's the conversion rate from dead civilians to zombies?
I haven't played for a while, but I remember the rates being linked to the size of the relative armies. For example trolls and treant zombies would grow incredibly fast, as they come in stacks of 30 and 40, while spellcasters would only grow very slowly as a stack is 1-3.
The rate of zombie generation seemed fixed at 1 stack / time period, but the death rate of civilians seemed to depend on the size of the city, and how long it had been infected for.
This might have changed over the past 6 months though.