Thats a lot of trouble to deal with one figure. I think Pyre Spirits are gonna start popping up in a heck of a lot more armies these days just because they are so difficult to deal with and are so good against Limited Invis figs.

As for dealing with Corpheus with a gunner army? Its pretty simple. He can only really do 4 damage every other turn safely. For almost 40% of your points thats just not enough. Using ML you can safely feed him a shade or two, over 3 or 4 turns, and force him to push if its a mancatcher, while using your other 270 or so points to fight his 178. The battle gets lopsided pretty quicky. You have to be willing to make a few sacrafices (often the War krugg and the shades) but can make up the points of Corpheus. The situation doesn't always play out exactly as planned but the army can adapt for it.

Barrel made some good points and covered some things that I left out (dang, trying to one up me on my own thread!). A balanced army doesn't make it the best army. A good player can use a more focused army to roll over a balanced army, and come up with extreme tactics to deal with bad match ups. In the search to find the best army you should attempt to explore alternate ways to win those difficult match ups.