Complexity of bookmap content model

Is anyone else concerned about the complexity of this content model?

<!ELEMENT bookmap (((%title;) | (%booktitle;))?, 
                   (%bookmeta;)?, 
                   ( (%booklists;) |
                     (%draftintro;) | 
                     (%abstract;) |
                     (%dedication;) |
                     (%preface;))*,
                   (%chapter;)*, ( ( (%appendix;)*, (%notices;)?,
(%specialnotices;)*, (%amendments;)? ) | (%part;)* ), 
                   (%colophon;)?,
                   (%topicref; | %reltable;)*)>

I don't mind its size as much as its complexity.

Even with validating editors like XMetaL, content models with many
alternatives can be confusing. "I put an appendix in and now I can't put
a part in before it. Why not?"

Also: why do we want to allow multiple abstracts, dedications, prefaces,
etc.

I could imagine something more like:

<!ELEMENT bookmap (title, 
		bookmeta?, 
		frontmatter?, 
		chapter*, 
		part*, 
		backmatter?, 
		colophon?, 
		relationships? )

I would expect the elements frontmatter, backmatter and relationships to
be topicheads.

 Paul Prescod