I can't like huge army fights due to that toxic spawning reinforcement system. I avoid those kind of battles. The gauges on top of screens are also not a good statement on the ongoing battle, the ennemy gauge can refill lol, so you don't have a true overview of the battle's end (how many troops the ennemy still have in reality).
With the spawning system you have to memorize where the ennemy spanws on the map and take it in count if you are advancing on that same map.
It is possible to lose a battle where there was no chance of losing, due to that system. And to get useless and irrelevant casualties.