well there is the problem

no shadow magic.
But serriusly i'ts nice of Norman to point out that a horde of 40 spear elfs whit a mind razor on it could kill a steam tank.
So you mean that the 400+ point unit whit magic support could take on the steamtank.
Thats totaly true but one does wonder what else those 40 elves could have been doing and where that spell could have been used otherwise.
But indeed the best case senario and totaly not considering what else could be going on does indeed make the Stank look pretty bad.
Then again those 40 elves are going to die to my 6 pigion bombs and 2 mortars cause well if where talking best case hhhhm.