Guest Author

I would like to know if there is an option to import guest authors as authors of the imported/created/crawled posts in the "Generated Post Author" option filed? Because now there is only an option of Random user, Import crawled author and the registered authors. But I don't want to create multiple authors unders users(too many emails and passwords). What I am trying to achieve is to show main crawled site URL  as the author of the post not the actual name of the author. So I would create multiple guest authors(actual site urls) with the coauthor plugin and then define them in the settings under specific rule. An even cooler option would be if you could somehow add the option of site url as the name of the author:) Thanks for any help in advance