OK I'm a little confused here. Perhaps I should have said village shapes, not village objects. I have used the default village1-9 shapes that are already in the TE in my MA terrain. I assumed that as each of these was essentially a group of objects then each one would be a groupmaster.
While on the subject, what should bridge and delta objects be classified as in an MA terrain?
Thanks for your help Dux, I'll rebuild the tanktown one object at a time. I can try rotating and setting different properties one at a time between testing to see what's happening.