Copying sets of radio buttons in PDF forms instances rather than copies

I have a PDF form with six pages of multiple-choice questions, each handled with a set of three to four radio buttons. To avoid having to make, size and configure each button individually I tried copying and pasting them, but I found this seems to instance the buttons rather than cloning them - so not only does answering questions on one page affect questions on previous pages, but renaming subsequent sets also renames the earlier sets making the whole point moot.

For instance, if each set is named for chapter and question in the format "Ch1Q1", and I then copy set Ch1Q1 to chapter 2, selecting and renaming that copy to Ch2Q1 would also rename the original.

I can't see any other options for how Acrobat handles the paste procedure (clone vs instance, for example) or to unlink the pasted button sets from the sources. What's the secret? Should I be using the Duplicate Across Pages function?