User blog comment:IamJakuhoRaikoben/Chapter 456: Order, Review./@comment-24102956-20151013095648/@comment-7418318-20151013173113

I don't think it'd work that easily. If they can pinpoint LH that precisely, they could have just teleported straight into the cellar, shrunk LH and teleported out again without Fairy Tail even knowing they were there until they checked the basement.

Brandish's appearance in Lucy's home makes it quite apparent that either she or Marin can easily circumvent Freeds rune-barrier.

And even if the protective spells around LH itself work against them, they could still brink in a small elite-force right to the guild, without bothering to fight through the outer defenses.

That they do bother to fight FT's defense leads me to believe that they don't know the exact location of LH yet.

Then there are other problems with shrinking the place down. Thinks like possible floods, rips in the earth between the shrunken parts and the not shrunken parts, since Magolia is not an island as was already pointed out and all kinds of possible cross-effects between present magical stuff (like LH's protective spells or Jutsu Shiki) with Brandish's magic that might end up screwing things over...

Even if it's possible I think it's just not worth the effort and risk when they can just casually throw a few armies at FT without a care.