I don't know a variable in NS formula:

Optimal Thieves to Send = (Opponents' Resources * Max % Of Total) / Gains Per Thief / Racial Mod
Is it the number of soldiers, or total army (soldiers + specs + leets)? I assumed peasants don't count, although they help defending but NS doesn't kill peasants right?

The explanation below from utopia wiki doesn't make sense:

Kills up to a maximum of 13% enemy soldiers at a rate of 0.67 soldiers per thief. Also kills a much smaller amount of specialists and elites. Will affect all troops, even those that aren't home.
What if my target has no soldiers? If I follow the utopia wiki definition, my max damage will be 0 (because target has no soldiers).
What number should I use to represent the "Opponents' Resources" in the formula?

Years playing attackers I am now assigned for a hybrid, I am confused with this. LOL
Really appreciate your help guys.