I'll finish up some thoughts and return your hijacked thread ;)

I suppose the corporal could have recently completed his enlistment and returned to the homestead. Little brother or sister might give him extra motivation. The other Marines would be unnecessary elements and he could be a militia leader based on his active experience. If he saves Newt after being saved by Hicks, he could be killed-off. Edit: He could have a tatoo on his forearm to show Hicks. He could rig small canisters of compressed air or gas as improvised concussion grenades.

Another alternative to A3 was having the Sulaco simply met by an outbound ship. They could take on Ripley while she's still in stasis and/or Hicks and/or Bishop or they could have taken over the Sulaco and sent Newt back to Earth in their transport. Ripley and/or the others could wake up back in the sh**. Military and/or company and/or civil government investigators wanting to figure out WTF. They could use threats and/or the promise to help in the adoption of Newt. Maybe the colonists sent some samples somwhere else before being overrun.

For a more practical fan-edit, Ripley's pod could detect a medical problem and could be ejected towards the nearest help along with the dropship to automaticaly grasp and haul to the help and/or because something wrong was detected in the dropship. The Sulaco could be abandoned with the characters in stasis because of contamination or the powers setting up Hicks to take a fall with no witnesses. :)