Simple, we have open-topped fast skimmer transports(albeit with the armour of tissue paper)32" charges?? how the heck do yall manage that??
HAH! In your dreams maybe. First off that retinue of Termies can take a Psycannon as well as the Grand master can take one. Thats upto 6 Str 6 shots at upto 36" 3 of which will hit on a 2+ and all of which will wound on 2+ and will deny you any Invulnerable save what so ever including your precious shadow field and at AP4 will deny you your regular saves as well. Your shadow field cant save you from a squads worth of Str 6 Power Weapons in HtH. A single wound from the Psycannon OR the Grey Knights Nemisis Force Weapons will cause Instant Death on your flimsy Archon. Heck a REGULAR Grey Knight can splatter your Archon just as easy as the Termies can. Archon *yawn*. Not to be mean or anything but theres a reason the DE codex is being re-written other than that its just plain old.A single archon will take the grandmaster and his retinue on and win.