Multiple Heads with poses

fireblast

I tried to make a three-headed dragon with DAZ Dragon 3. I took two extra dragon figures, shrunk everything except the head, neck, and chest (for alignment purposes) to nothing, then aligned them with the main body and parented them to it. The problem happens when I try to pose the dragon. Some poses work fine. Other poses, however, have the extra two heads become offset. I tried locking them. I tried fitting them to the main dragon. Nothing I tried works.

Poses included in the DAZ Dragon 3 base product and DAZ Dragon 3, Victoria 8 and Michael 8 Poses seem to work fine. The DAZ Dragon 3 Fantasy Poses not only doesn't work, but also makes the dragon very tiny and upside-down (does not happen with a regular dragon). Dragon Master Poses, Cinematic Poses for DAZ Dragon 3, and Dragon Trainer's Toolbox do not work. Oriental Dragon and DAZ Dragon 3 Poses works with some poses but not others, though the offset is less severe. The Dragon Master Pose Control works fine. I do not currently own any other dragon pose sets.

Is there some way to fix this problem, or will I have to not use those poses?