Impossible+

[N3MES1S]

\steam\steamapps\common\kings bounty armored princess\sessions\addon\ses.kfs -> hero.txt

There u can modify parameters such how exp gain the hero on level up, how many ls start with, the initial army, how many start rage, runes, etc.

Theres also a armygen.lua, with the scripts for army generation, if u can understand the code, u can manage to spawn more or less units on the stacks.