Thanks John.
I thought about the consequences of doing it this way too, where each post would have to be edited one by one. I still thought it would be better, rather than having a separate page which is ‘disconnected’ from the posts. But after some more thought, I agree with you.
So I set up a relationship field, set it to posts and the ‘featured’ category and the Return Format as Post ID. With the following code I got it to work (only posting this in case it is useful for someone else):
<?php
$posts = get_field('feature_ordering', 109); //Page ID number
if( $posts ):
foreach( $posts as $post):
setup_postdata($post); ?>
<div class="featured">
<?php the_title(); //etc... ?>
</div>
<?php endforeach;
wp_reset_postdata();
endif;
?>
Thanks again though for the code and for making me go with the better way 🙂