How to combine all those combat percentage modifiers into one complete formula?

[Atherys]

I've tried adding and multiplying, but the result just won't make sense. I've tried consulting the manual as well, but no avail. I'm guessing it's because some modifiers only affect certain variables, such as only HP or only attack. Should I add or multiply the percentage separately for multiple values, like HP and attack?

I'd really appreciate if any of you proficient in this game can explain this in details to me. I know that I don't need to know any of this, still play the game by estimation and experience, and still be able to win. However, since all the numbers are provided in the prediction screen, I want to know what's truly behind the curtains.

I'm also one of the few who follow the details of the outcome for each combat round (like who shoots who and whether the target returns fire). It's just my personal enjoyment. Knowing the calculation will ease my mind a lot.

[JeanleChauve]

The best way to understand these calculations is to use a unit made up of a single subunit.
You multiply offensive power by all modifiers preceding cumulative modifier one after the other.
This is equivalent to multiplying offensive power by cumulative modifier which did the math for you.

The calculation with a unit comprising several different subunits becomes more complex because each subunit has a different offensive power and modifiers.
The only way to calculate this cumulative modifier is to do it for each subunit separately and then average.

The calculation with several units of different type and/or positioned on different hexes is too complex.

The odds are calculated by comparing the modified offensive power with the modified defensive power, but be careful, because these powers only take into account visible units (recon) and the average of the leader bonuses.

Even if the odds are in your favour, events can tip the fight: the loss of a leader will give a 50% penalty, a unit with low morale combined with low readiness/integrity can retreat too early and reduce the encirclement bonus...

If this explanation is not enough for you, I can make a video of it.