How to effectively use quick battles (autobattles)?

To be honest, that's how it is for me! I've noticed that if I attack, say, with Elves against Archers, they immediately shoot at the Elf, and we lose one, especially when quickly deploying Centaurs. Based on this, I came to that conclusion.

It's simpler and more prosaic. Archers shoot at Centaurs because they immediately charge forward. That's why I always separate individual Centaurs when breaking through archer formations and send them forward immediately. The other day, playing as Fortress on map 111, I got Boots of Speed for 29 gold. I lost 4 Ogres and 5 Centaurs, using starting heroes and armies without ambushes or magic. Kirre was level 1 with his original stats of 1-3-1-1. I didn't take Elves into the battle. It's a pity my opponent restarted the game :( .