Before the carnage started.
In addition to the alignment wheel we also added a second new mechanic:
Most of the park guests are holding $100 bills. Each player starts with only their hero, but has a roster of units and abilities that can be purchased with money.
We've always achieved good levels of accidental destruction, but I wanted to ensure active malice towards the innocent bystanders.
Killing a bystander automatically gives you their money, so the park guests essentially became currency to buy more squads.