Heh...
Well do you really want your own scales to cover your territory
Other than heat probably...
I agree that Iron Will is problimatic, as you have to position the mage so that only the spiders are in range otherwise he casts it on your archers (uggg....), but... its easy to get to quickly, and its a tool in the toolbox if you really need it. Also you probably don't need to cover 100% of your spiders, just enough so that the enemy wastes some casts on them.
If we're talking paralyze here it will target the closest correct? So you can stick your spam up front to draw off the first wave, then your quickened spiders should still be able to get a few into the rear/flanks of the enemy.
And if you're willing to take another hit in your scales somewhere (or drop astral to 4) you can remain awake with a dom of 7 as the glyph starts with dom4 so bumping it is quite cheap.