Arryn,
you are right, I should have been a bit more elaborate about this one.
Mainly it was the usual mix which which tends to lead to success for my forces:
Some enemies are enslaved - leading to fighting among themselves - while my mindbLasters do their job of stuning/killing more troops to great effect due to the additional time they get due to the infighting.
The Vine Ogres took the brunt of the infantry attack - giving my bLasters even more time to do their work - breaking the infantry fairly fast (thus sustaining only light casualties, except for the fodder which did their job of being fodder

).
In addition the knights were put on hold/attack archers (my standard setup for them) and tore through the ranks of the crossbowmen and commanders later on.
The crossbowmen were fairly inefficient due to the decent protection of my troops and the long range (they were trying to take out the Illithid Soldiers mainly).
Overall I would say that my mages played actually a fairly minor role (except for the VERY important enslaves). The major number of the kills were caused due to the stuned enemy troops who were just standing there waiting to be killed after their other forces routed. I seem to recall that about 40 were killed after the battle was won.
But my mages surely could have played a larger role if I assigned gems to them. Due to no gems they are limited to 4S and tend to mainly cast protection spells on themself after the scripted spells are cast.
CharonJr