[PvK]

Since it Vengeance Of The Dead a magical nightmare attack, I'm not sure the realism argument holds - maybe if the victim doesn't kill the hordes in time, the dream ends with them carrying him away to Hades. Or not.

On principle I agree I'd prefer it if a time limit resulted in a draw and not an attacker win.

As far as balance goes, I think VOTD is a nicely thematic anti-SC spell. Similarly, I personally think the game is more interesting when not dominated by SC's.

Ideally, I think I'd prefer to see time limits resulting in a draw, and VOTD being more interesting, such as including the slain units more like they were in life, for example with different types of undead based on who was killed, slain mages retaining some of their magic, some slain warriors as armed soulless or longdead, slain elephants as undead elephants, etc, but also not multiplied by killing souls during VOTD - it doesn't make sense to me that killing a returning soul (or mindless living unit) would cause it to appear twice in the next VOTD attack.