print "$_  # Length ", length( ( keys %{ $HoHoA{ $_ } } )[ 0 ] ), "\n"
  for
  map $_->[ 0 ],
  sort { $a->[ 1 ] <=> $b->[ 1 ] || $a->[ 2 ] <=> $b->[ 2 ] }
  map [ $_, length( ( keys %{ $HoHoA{ $_ } } )[ 0 ] ), substr( $_, 3 )
+ ],
  keys %HoHoA;

__END__
set2  # Length 3
set3  # Length 3
set4  # Length 4
set1  # Length 7

[download]
If you have no preference on the ordering of ties, then the ST part can be a bit simpler: 
  map $_->[ 0 ],
  sort { $a->[ 1 ] <=> $b->[ 1 ] }
  map [ $_, length( ( keys %{ $HoHoA{ $_ } } )[ 0 ] ) ],
  keys %HoHoA;

[download]
These solutions assume that all the secondary hashes contain at least one key.

the lowliest monk

In reply to Re: Sorting HoHoA based on Length of Second Key by tlm
in thread Sorting HoHoA based on Length of Second Key by Anonymous Monk

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