G'day QM,

TMTOWTDI. Here's "pm_1201500_dict_char_ordered_count.pl":

#!/usr/bin/env perl

use strict;
use warnings;

use constant MIN_LENGTH => 10; # 1+2+3+4

RECORD:
while (<>) {
    next RECORD unless MIN_LENGTH < length;
    next RECORD unless /^([a-z]+)$/;
    my %char_count_of;
    $char_count_of{substr $1, $_, 1}++ for 0 .. length($1) - 1;

    my $check = 1;

    for (sort { $a <=> $b } values %char_count_of) {
        next RECORD unless $_ eq $check++;
    }

    print;
}
[download]

Looking for words with ten characters or more:

$ pm_1201500_dict_char_ordered_count.pl /usr/share/dict/words
beerbibber
chachalaca
isoosmosis
kotukutuku
rememberer
sereneness
sleeveless
[download]

Changing MIN_LENGTH:

use constant MIN_LENGTH => 6; # 1+2+3
[download]

I get all of those ten-character words, interspersed amongst over a hundred six-character words, starting with

$ pm_1201500_dict_char_ordered_count.pl /usr/share/dict/words | head -
+5
allele
amamau
ananas
ananda
annona
[download]

and ending with

$ pm_1201500_dict_char_ordered_count.pl /usr/share/dict/words | tail -
+5
ubussu
venene
wedded
weeded
weewow
[download]