Is every post represented in the repeater?
You could create pre_get_posts filter in WP https://codex.wordpress.org/Plugin_API/Action_Reference/pre_get_posts. In this filter loop through the repeater, get all the post ID’s in the order that they should be displayed. Then alter the query to main query to include the ‘post__in’ argument with the array of post IDs and set the orderby argument to ‘post__in’. https://codex.wordpress.org/Class_Reference/WP_Query#Order_.26_Orderby_Parameters
