A recent mistake by Funcom highlighted an imbalance in how thralls are leveled up.
The mistake allowed players to level multiple thralls at the same time to level 20 by killing one Golem in the new dungeon.
Granted in PvE or PvEC slow leveling thralls gives players something to do. But in PvP after all the thrall nerfs an entire army of thralls can be wiped out in less than one raid time and yet the same army would take many raid times to train. This seems very unbalanced and i think that it would be much more enjoyable for everyone if the thrall xp gain was greatly increased so that thralls could be replaced somewhere closer to the time that it takes to kill them.