The question is, when is it required to make difficult terrain rolls when charging. It states that when a model "has to" move through difficult terrain, then they must take the test. But with random charge distances, how would one know if a model has to make the test or not before the distance is even determined.
The thread here describes in much better detail what i'm trying to ask, please read.
http://www.warseer.com/forums/showthread.php?346573-Charge-Distance-difficult-terrain
For some additional info on the matter here's the FAQ update:
Page 22 ¬ Charge Move, Charging Through Difficult Terrain.
Change the first sentence to read “If, when charging, one or
more models have to move through difficult terrain in order to
reach the enemy by the shortest possible route, the unit must
make a Difficult Terrain test (see page 90).”
Personally i think we should include Nurgling Chieftain's solution as a house ruling. But of course i'd like to see what the rest of us think on the matter