You're close. You just need to go one level deeper into the array that get_field
is returning.
<?php foreach( $post_objects as $array): ?>
<?php foreach( $array as $obj): ?>
<?php setup_postdata($obj); ?>
<div class="mt-one-half">
<h3><a href="<?php echo get_permalink(); ?>"><?php echo get_the_title(); ?></a></h3>
<?php the_excerpt(); ?>
</div>
<?php endforeach; ?>
<?php wp_reset_postdata(); ?>
<?php endforeach; ?>
//etc... as before