I figure she could, in most cases, focus on estimating villages affected, rather than number of individuals hurt. This would include supplies, currency, horses, etc.. and cover places we know of like Cyrra, Thalassa's town, the northern Amazons, places suggested by victims, in DREAMWORKER and even Higuchi. That would be more doable, as it would be impossible to know exactly how many died, were injured, lost homes. If she couldn't do something positive for the affected town (like Higuchi), she could count towns helped post-Destroyer period. I actually think she made good progress by helping Greek and northern Amazons, Amphipolis, Poteidaia, the place where girls were kidnapped, etc.

I'm not sure about including the Centaurs or other battles like in Corinth, as those seemed more wars between equal armies over territory, loot, etc. As to the Norseland and Chin, she did return later to rectify ills she'd set in motion during the past.