They can't mobilize the entire undead horde at once, and Sam can stir up some serious trouble from within if we run into that T-Rex.  That they outnumber our forces won't matter since they're not getting out that fast.<br/><br/>If we go in, Hallow's pretty much a given in my eyes.  The real question for the Augury?  Is it wise to go in at all?  The worry that inspired the Augury is whether the lever's even there anymore, or if it's been destroyed/sabotaged.