Yesterday I tried something of the above- previsou games I've been known to field a balnaced force, but definately with magic and warmachines.
Knowning my dwarf opponent knew this, I gambled and went with no warmachines and no wizards (thogh I did have a priest and a capatsus with the bound spell burning head). Burning head worked a treat as the dwarf player had used all his dice dispelling the prayer (I couldnt help but smirk when I revealed the spell as I was lined up along his lines). Caused a few casulties and shook his line.
Overall though, I lost- his shooting was outstanding in the first few turns and decimated by statetroops.
I like throwing a few curve balls in though, get my opponent surprised and having to shift his focus- they are more likely to make mistakes than if you field the 'standard' army you do.
Obvisouly the one flaw with this is that im starting to get a reputation for curve-balls and so it is unlikely to work as well! (As long as I keep the opponent second guessing, i dont mind)