Insert columns in a WordPress admin table in specific order (example).

insert-columns-in-order.php

<?php
function set_custom_CPT_columns( $columns ) { 
	
	//Insert 'Until' before 'date'
	$index = array_search( "date", array_keys( $columns ) );
	
	if( $index !== false ){
		
		$before = array_slice( $columns, 0, $index );
		$after =  array_splice( $columns, $index, count( $columns ) );
		$columns = $before + array( 'until' => __( 'Until' ) ) + $after;
		
	}
	
	//Insert columns after 'title'
	$index = array_search( "title", array_keys( $columns ) );
	
	if( $index !== false ){
		
		$before = array_slice( $columns, 0, $index + 1 );
		$after =  array_splice( $columns, $index + 1, count( $columns ) );
		$columns = $before + array(  
			'p_excerpt' => __( 'Details', 'textdomain' ),
			'p_shortcode' => __( 'Shortcode', 'textdomain' ), 
			'p_image' => __( 'Preview' ) 
		) + $after;
		
	}
	
	return $columns; 
} 

add_filter( 'manage_edit-CPT_columns', 'set_custom_CPT_columns', 50 );
?>