Instead of making the same bosses each time, I suggest we do a mix-n-match.
Example:
Tier 1:
Riots, Strkes, [Another collective of angry people].
Tier 2:
Terrorists, Bank Robbers, [Some other form of terrorism].
Tier 3:
Church Fire, School Flood, [another natural disaster].
Now what happens is that it selects the bosses randomly, so in one game you might have Strikes, Terrorists, Church Fire. While in the next game you have Riots, Bank Robbers, School Flood. It adds replayability to the map and a level of mystery (maybe some tiers are unlock-only? Maybe some are only possible to have randomly if you do certain life-quests?