Is Ermor "broken"?

[NTJedi]

onomastikon ...

try playing against Ermor with a setting of AI Difficult.
Guaranteed to shake your world.

[General Tacticus]

The 5 skeletons Version of this spell, however, is very powerful. 5 undead commanders casting it non-stop annihilated my special "destroy Ermor quick" force of 50 Ulm super heavy infantry supported by 25 "banish undead" priests. 12 of which were in the hall of fame at this point, from banishing massive numbers of undeads I was actually slowly grinding ahead, but my infantry finally routed (enough is enough ! they must have thought) and my priests quickly died.