multible shortcodes (for differnt values) with one function

Edit your function to accept a parameter, e.g. function modell_nach_personenzahl( $value ) {
Edit your meta query to accept this parameter, e.g. 'value' => $value

Then register a bunch of shortcodes:

for ( $i = 1; $i <= 7; $i++ ) {
    add_shortcode( "shortcode-name-{$i}", function() use ( $i ) {
        modell_nach_personenzahl( $i );
    } );
}

Then just use [shortcode-name-1], [shortcode-name-2], etc.