Stronger Enemies
Classic enemies now have nearly the same armor stat bonuses as vanilla Tactician: +60% physical armor, +40% magic armor. They do not receive a vitality bonus like Tactician enemies, though.
Tactician enemies now have +75% physical armor, +50% magic armor, +60% damage (default is +50%), and +0.5m movement speed,
A buff to NPCs if you started in Classic and found the challenge lacking but don’t want to start over, or a slight buff to Tactician NPCs for some extra difficulty. I recommend trying Enemy Randomization if this is still not difficult enough.