Forget about point costs, who cares if its fair if its fun?
In fact fielding overwhelming odds can be very exciting.
This battle represents an Earth Expeditonary Force.
would suggest 4-1 odds with the corp forces starting in the middle.The objective is to survive.

Side one: Any complete corporate force,at least 15 - 20 guys armed with rifles and heavies.

Side two: As many models with only hand weapons as you can find.
Acting as squads only, without individuals.
The masses would be zombies, mutants, freaks, weirdoes, etc.
Their objective is to devour the corporate forces.