On the Homecoming level, you can send a single unit into the ruined temple (or even take the book, if you send your j-man and keep your other units at a distance). The extra units and enemy army won't appear until you bring a second unit near the ruined temple.
Try this:
Send your j-man, and position him just north of where the warrior circle will appear. When your other units approach and the enemy suddenly appears, start un-healing wights and as soon as you get control of the dorfs, make them stop throwing. With both j-men, you can eliminate the wights and save all but a few lowly warriors!
