Much to the frustration of the players at my venue, I play with this army (or a variant) quite a bit. I like to drop the CP's and the Imp and add the Shieldtome. Now all that Mage Spawn are immune to all range while in base with Nim, except from precision. And against that, they will have a 19 defense.
There had better be more Mage Spawn released in the future to give Nim a purpose in life! :)

I use the Shieldtome Variation normally, but considering players at my venue are getting used to locking down range combat, I figured I would rather have healing support for Nim and such instead of worrying about being shot. Big Bounders like Khan Rava have more things to worry about than damaging Nim.