I have a few objects with that sort of scale problem as well.
Since .obj files aren't native to DAZ/Studio you can put them into any folder you want.  One called imported objects with sub folders named for the various objects comes to mind as sensible.  I usually just rescale the object if that sort of thing happens.  The textures are usually of a scale that allows them to appear reasonable at a normal size for the DAZ figures.  You can usually use the size parameter to rescale.