What happens when you add a new article by Author3 ?
/blog/author1 is a list of 4 articles
/blog/writer2 is a list of 6 different articles
/blog/writer3 is a list of 1 article?
/blog is a list of recent 10 articles (the 1+4+6 from the two writers), /blog/page2 getting the 11th article ?
If this is the case, I would not worry too much about it. Homepage is set to recent articles and each author has it's own page. As you add/update more articles, more authors maybe, it's more different. It's a dynamic blog. A typical structure. I would not worry too much about it.
If you are concerned, you can set a noindex on your write pages.