@fatherbushido: The problem is experienced players use dance cheat to kill less experienced players.
A noob will suicide an entire army against a dancing cav while the range units behind cav kills the army k/d -> infinity.
The usual way to fight that is to approach owns army to enemy dancer, under fire, because only accuracy when very close can harm dancer, but you are already losing a lot in doing so and the cav/army can retreat and dance again.
It is a cheat because many abuse it to wipe enemies or win a fight with way less soldiers.
The original problem of post was broader, people retreat hero or a small portion of front army to lure enemy army to chase them while the majority of army is shooting the unattended/noob army. That's why change of target is suggested.
And the promotion animation is a problem when it happens to a front unit absorbing all missiles while your units die. This is ofc not under your control and it happens both sides but you can be so unlucky that most your army dies to it before you are benefited from it.