Yes, in general it´s possible to modify the dialog content! I do something similar. Check out this post from years ago: link
You can remove certain properties form the history. Tip: The version comment field is very useful inside the history...once you taught your users to *use* it.
BUT: I am not sure if you can integrate the relationship information in a meaningful way. In my case I overwrite the file properties in the Form with the corresponding relationship files. This way we can see the files inside the version dialog. But I use a highly customized ItemType for Documents. The xpath query in the code looks like it allows us to add sublevel information, but I never tried.
You can add a history container to the Document Files ItemType, but I never tried what happened when you do this. If you want to try this, definitely use a test database to avoid you need to clean up the history later.
I once used 11SP9 but don´t remember the "File Revisions" under "Views". Maybe this function is only available in combination with the Office Connector?
