Actually I do not want a titlePage for texts A and B, but I can’t see another way to provide a title to these texts, given that head is not allowed. The title of text A is not the heading of the front matter and some heading of the body would come too late (after the front matter).
The heading said all there was to say.
This is to test some back matter in the first text child of group
This is to test some back matter in the second text child of group