Heroes 5.5 WarGame Edition - Tactical Edition.

How? Not to engage in active combat with enemy troops when all of their troops have only a minimally positive luck value? To adopt a defensive strategy, prolonging the battle and minimizing the chances of defeat due to luck triggering? That's not an option.

Grant creatures abilities whose effectiveness doesn't depend on luck (like the lightning spell of druids).

If a battle is just a game of chance for the player, then that's one thing.

The battle is indeed a game of chance. My approach to the game involves not only calculating everything but also minimizing risks and taking advantage of luck. So, in this case: if you see that the enemy's luck is 5, try to anticipate something, at least estimate whether it will trigger now, considering how it has triggered before.