Why Rman taking multiple backups of controlfile with each backup command in one script

Hi,I would be grateful if you replied my questions,
1- Why Rman taking multiple backups of controlfile with each backup command
2-Do we need to mention 'alter system archive log current'
3-If backup mode is archived and we are expecting insert during backup then what should we add in our backup script?
4-Why we are using 'Include current controlfile' syntax in rman backup script when we already got controlfile backup during database backup script,
 
Script have multiple backup commands, its log shows backup of controlfile multiple times:
       {       backup (database include current controlfile);
              sql 'alter system archive log current';
                  backup archivelog all;