Yeah. It simply depends which is closer. However, chancer are like 80/20 to attack a remaining enemy stack if there is one in range, otherwise, it will go for your own stack.
This is why if I decide to try an undead army, I should make it:
Black Knights
Ancient Vampires
Vampires
Necromancers
Demonologists
and Bone dragons + skeleton archers in reserve. The ghosts are great, but they are simply too damn unreliable. If they outgrow your leadership twice, it will take at least 2 rounds of suffering some losses to drop them down to their normal stack size.
I for one, would love if there was something in the game to regulate that condition - whether to drain souls or stay at max leadership. But there isn't one and I'll have to find other options, and of course, adapt my tactics
