I forgot to emphasize, interlink the articles in a series to help users jump through the different parts of the articles in the same series help.
On breeds of unicorns, you want visitors to be able to freely jump through the different unicorn breeds without back space.
Although, if each breeds of unicorn do not justify a page on its own. Grouping them can be more helpful in ranking for "unicorn breed" instead of targetted "short horned unicorns" single page. Again, think about what is useful in terms of information and necessity.
You will have to be creative and work to figure out how to help your visitors navigate through your article content structure.