Berserker, a report of compatibility issue with Mixed Neutrals and Neutral Unit Bonuses (script 21, option 57).
Check my debug+save here

To reproduce the issue, you need to
1. Load my save. Alternatively, you can create a game with Mixed Neutrals and option 57 on, pass a week to let the neutrals grow
2. Attack any Neutrals, check their stats.
3. Run away
4. Load a save before fighting, and fight the same stack.
5. Check how much they are buffed now.

And you will see the neutrals gets more and more stats by repeating these steps, typicially it ends up like this.
Luckily, this can be resolved by relaunching the exctutable (H3era.exe). All will revert.