Have you tried content generation using Generic Setup? The following example should reset the content generated by setupPortalContent():
Add folder named structure under your site policy product's default profile folder (e.g. src/my.site.policy/my/site/policy/profiles/default/structure/).
Under that folder, add a new file named .delete with content
events front-page Members news
Under the same folder, add a new file named .objects with content
front-page,Document
Still under the same folder, add a new file named front-page with content
id: front-page title: Foo description: Bar Content-Type: text/html <p>Hello World!</p>
The new Plone site created with this policy should contain only the front-page described above. (Note that the new front-page has the initial state of its default workflow, which is private by default.) The easiest way to experiment with content generation further, I think, is to just create something, export Content-step from portal_setup and examine the results. Also the Generic Setup Quick Reference by Six Feet Up gives an overview for content generation support in Generic Setup. 总结： 所有Archtype和dexterity内容类型都可以采用这种structure方式来预置内容对象。