MArcomage

I would think Nature and Unliving to be polar opposites in most cases. Even so, I know that nature elementals exist in several sources of lore.

A swamp thing would certainly be Nature, but I wouldn't see it as being a "nature elemental" per se.

Would the percentages round up or down? If the opponent only had three recruits and the conditions were right for the effect to occur, would we expect to see it decreased by one or by zero?

Rounded up I think. That way some recruits are always lost even if its only 1.

We use standard rounding as default. When you want use different rounding, or add some maximum or minimum, you need to specify it.