Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

In the area south of Beregost, sometimes multiple wyverns will spawn in the exact same place and their pathing "footprint" or whatever determines collision will overlap, making it impossible for them to move and also difficult and sometimes impossible to get close enough to attack with melee. This forces you to take all but one out with ranged weapons in order to even be able to attack the last one with melee. This has happened to me 3 times, once with one character and twice just now with another.

Multiple spawns aren't staggered and not taking into account of an existing object in the same place before creating more, hence the result.

Well, i believe, in next update, they should stop being clipped into each other in most cases.
I doubt it's possible to remove that bug completely, but in my testing, they did finally spawn in different places.