I concur, it's bad practice. The split over packages is brittle and unnecessary. Done with common modules (untested):

package Foo;
use Moose;
use Sub::Exporter -setup => {exports => [qw(procedure1 procedure2)]};

# OO stuff comes here

has some_attribute …

sub some_method {
    my ($self, @args) = @_;
    …
}

# procedural stuff comes here

sub procedure1 {
    my $self = __PACKAGE__->new; # if needed
    my @args = @_;
    …
}

sub procedure2 {
    my $self = __PACKAGE__->new; # if needed
    my @args = @_;
    …
}

1;
[download]

Usage from the main code:

use Foo qw(procedure1);

procedure1(foo bar quux);

my $f = Foo->new(some_attribute => baz);
$f->some_method;
[download]