What's a better question... Where's the REST of them? There were 3 Dresellian scouts who went along with them, as per the hangar scenes in ROTJ (at least 3 Dresellians are seen walking into the Tyderium, so unless they were just checking out the interior I'd say they went along) and the Shuttle can hold many more troops... It's likely many more went.
As a Dresselian I can attest that we are known to check out the upholstery of shuttle then run from the fight.
How much would I have loved it if the Dresselians were shown with their slug firing weapons (as opposed to blasters) knocking off stormies?
Good point JJ.