En esta web pone que los <section> pueden contener <article> y también viceversa.
http://html5doctor.com/the-article-element/
An <article> with <section>s. You can use the <section> element to split the article into logical groups of content with headings:
Código HTML:
Ver original <p>The apple is the pomaceous fruit of the apple tree...
</p>
<p>These bright red apples are the most common found in many supermarkets...
</p>
<p>These juicy, green apples make a great filling for apple pies...
</p>
A <section> containing <article>s
Código HTML:
Ver original <h1>Articles on: Fruit
</h1>
<p>The apple is the pomaceous fruit of the apple tree...
</p>
<p>The orange is a hybrid of ancient cultivated origin, possibly between pomelo and tangerine...
</p>
<p>Bananas come in a variety of sizes and colors when ripe, including yellow, purple, and red...
</p>