I have been trying for a few days now to make my layouts more efficient by converting from using several levels of nested LinearLayouts to one RelativeLay
For positioning to work on RelativeLayout you need to set the layout_* parameters in the include file, not in the main layout file. That way
main_layout.xml
....
.....
content_layout.xml
....
This is obviously not what us developers want, but it's the only solution I've found to avoid duplicating xml