Updated: added missing declaration per trippledubs's report below.

A somewhat more optimal version that avoids multiple greps and re-testing of some conditions:

#! perl -slw
use strict;

my @data = qw[
    alpha bravo charlie delta east echo exit foxtrot golf hotel india 
+juliet kilo lima mike
    november oscar papa quebec romeo sierra tango uniform victor whisk
+ey xray yankee zulu
];
my @sortedData;
my( @rindex, @eindex, @oindex );

push @{ $data[ $_ ] =~ m[r] ? \@rindex : $data[ $_ ] =~ m[^e] ? \@eind
+ex : \@oindex }, $_ for 0 .. $#data;

my @rsorted = sort{         $data[ $a ]         cmp         $data[ $b 
+]         } @rindex;
my @esorted = sort{ substr( $data[ $a ], 2, 1 ) cmp substr( $data[ $b 
+], 2, 1 ) } @eindex;
my @osorted = sort{ substr( $data[ $b ], -1 )   cmp substr( $data[ $a 
+], -1 )   } @oindex;

@sortedData[ @rindex, @eindex, @oindex ] = @data[ @rsorted, @esorted, 
+@osorted ];

print for @sortedData;
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