When dealing with parallel arrays, the bond between them is the indexes. That means you need to sort the indexes.

my @eles  = ( 1, 5, 3 );
my @prios = ( 5, 2, 1 );

my @idxes =  sort { $prios[$a] <=> $prios[$b] } 0..$#eles;

@eles  = @eles [ @idxes ];
@prios = @prios[ @idxes ];

print(join(', ', @eles), "\n");
[download]