Getting only associated posts

I’m working on a bit of code but am completely stuck on how to do this properly. I’m using the Advanced Custom Fields plugin to create relationships between my custom post types. The main post type is Clients, then I’ve associated each particular client to my certain other posts in other post types. What I want to achieve is each client to display with a list of the associated other posts. Here is what I have so far.

<?php
   $loop = new WP_Query( array( 'post_type' => 'clients', 'posts_per_page' => 10 ) );
   $ids = get_field('attach_to_client', false, false);

   $query = new WP_Query(array(
	'post_type'      	=> array('research', 'project_brief','persona','task_models', 'user_stories', 'style_guide'),
	'posts_per_page'	=> -1,
	'post__in'		=> $ids,
	'post_status'		=> 'any',
    'orderby'        	=> 'modified',
));
 ?>
<?php if($loop->have_posts()) : ?>
<?php while ( $loop->have_posts() ) : $loop->the_post(); ?>
<div>
<h3><?php the_title(); ?></h3>
<?php if ($query->have_posts()) : ?>
<ul>
<?php
	while($query->have_posts()) :
		$query->the_post();
?>
	<li><?php the_title(); ?></li>

<?php endwhile; ?>
</ul>
<?php else: ?>

      <p>Oops, there are no posts.</p>

<?php endif; ?>
</div>
<?php endwhile; endif; wp_reset_query(); ?>

This gives me every client but also all the posts too. It doesn’t take into consideration whether or not it’s actually been associated. How do I get it to only show the clients that have something posted in association with the client then hide the rest.