Argument list too long - Unix

Question

This scripts will sort the files by date then move the first 2500 files to another directory.
When I run below scripts, system prompt out Argument list too long msg. Anyone can help me enhance the scripts ? Thanks

NUM_OF_FILES=2500
FROM_DIRECTORY=/apps/data01/RAID/RC/MD/IN_MSC/ERC/in
DESTINATION_DIRECTORY=/apps/data01/RAID/RC/MD/IN_MSC/ERC/in_load

if [ ! -d $DESTINATION_DIRECTORY ]  
        then  
                echo "unused_file directory does not exist!"  
        mkdir $DESTINATION_DIRECTORY   
        echo "$DESTINATION_DIRECTORY directory created!"  
else   
        echo "$DESTINATION_DIRECTORY exist!"    
fi  


echo "Moving $NUM_OF_FILES oldest files to $DESTINATION_DIRECTORY directory"  

ls -tr  $FROM_DIRECTORY/MSCERC*.Z|head -$NUM_OF_FILES |
    xargs -i sh -c "mv {} $DESTINATION_DIRECTORY"