I may be able to help, but need some more details.
you say that those two parts being in two "completely differents" modules. what kind of separation is there between them (parents, childrens, separate files....)

I am not sure where you found this anchoritem properties (no computer at hand...).
I usually use the bunch of anchors.* properties you can find in this doc : http://doc.qt.io/qt-5/qml-qtquick-item.html

there are several kind of anchors and dedicated properties for each. anchors.fill for exemple sets all sides to match another item, but you can also align only some sides or the vertical and horizontal center as you wish.
maybe explain what you need the anchored item do relative to the target (fill it, center in it, right align...).