with different people responsible for each one.
With my cd2 necro, I liked to cast IM on a group, and then Attract on one or two of the monsters, repeating till all were dead.
In co-op I enjoyed decrepify till someone had gotten a kill, then amp + Ce.
Curses have a large impact on the monster(s) you fight. IMHO the impact you, the player, desires is not static but changes with through-out the individual battles. To me it seems it would be very hard to co-ordinate the cursing amoung your brotherhood of the undead.
Ok, that said...
you could easily ignore 'optimal cursing': just take a more blizzard approach and brute-force your way through the whole thing and never notice. eh, it might even be faster that way.