The notion of "reduced net aggression" requires a system for classifying all of aggression's varying forms into commensurable units. It's relatively non-controversial to assert that picking a pocket is less onerous than assault, which is in turn less onerous than murder, but unitizing these forms of aggression for bulk comparison is a different story entirely.
Does it take 2.5 armed robberies to equal a rape, or 3.1?
Is the prevention of two murders a fair trade for 100 unreasonable searches?
Even when aggression is measurable in known units, it's not necessarily true that the factor of aggression itself is quantifiable in those units. If I can reduce the taxes of Person A by two dollars in trade for raising the taxes of Person B by only one dollar, is that a net reduction in overall aggression? What if Person A's two dollars would otherwise have been spent on country club initiation fees while Person B's one dollar would have otherwise been spent buying food for his starving child? Would the decrease in aggression versus Person A truly be commensurate with the increase in aggression versus Person B? The value of a dollar may be uniform for certain purposes, but it is highly subjective for most. Most people would agree that stealing a piece of 18 holes on the golf course is less onerous than stealing a baby's bottle of milk, even if the dollar values of the two say otherwise.
Even leaving such questions aside, precisely why should Person A accept an obligation to be aggressed against more, so that Person B will be aggressed against less, specious "overall net" claims notwithstanding? Under what moral calculus should anyone be considered fair game for aggression in any amount?
Let's talk about it.