Why do you fight?
If you are not fighting for your country, then you are fighting for rewards. This is beyond dispute.
If you are a leader of a country or a military unit, you must know how to extract the greatest possible benefit from these battles without exhausting your forces. You need to understand the basics of war, how to choose battles, and the extent of their impact.
1. Do not underestimate the attack bonus. An addition of just 5% can change a lot. I am astonished by countries and military units that issue orders for battles with a negative attack bonus, thereby weakening their soldiers' strength. At the same time, if you choose a battle with a positive bonus and add to it the country order and the military unit order, you will help your soldiers advance in military ranks.
2. Military ranks. Some overlook the bonus granted by military rank, arguing that it is small, seeing the number as insignificant and not worth it. But the frightening truth is that even an addition of 1% means a great deal, because it raises the base damage value and reduces the production cost per 1k damage.
3. Do not choose battles randomly. Why enter a battle just because it has a high attack bonus? Is your primary goal simply to hit? Certainly not. You want yourself and your soldiers to obtain a reward that is worthwhile. Therefore, choose battles taking place between major countries that are known for fierce, grinding wars, to ensure that even your lowest-ranked soldier receives at least green equipment.
4. Monitor the time. What is the benefit of entering a battle that will end shortly, where your soldiers will not have time to unleash all they have? Any battle with less than 3 hours left is a battle that is already over.
Conclusion: If you are a leader who cares about your soldiers, you must take all factors into account. The majority of players focus only on the economy and have no impact on wars, but if you choose the right battles, even they will deliver respectable results for you.
Summary: A successful battle is one that offers:
1. The highest attack bonus.
2. The highest reward value (by which I mean equipment).
3. The longest possible remaining duration.