How do a group of aliens defend against the mecha of mankind?! Mankind seems to think that its top of the food chain. But its not out in the depths of interstellar space. There are empires whose cosmic legacies stretch back millions of years.There are artificial & cybernetic life forms that can take out anyone who crosses their world's borders.
The Greys have always been a source of absolute terror & horror within our campaigns. After the Fall of Mankind campaign has the Greys using artifical life forms to police, administrate, and even kidnap humans to work their colonies. So here's where Independence Games Artificial: Robots of The Clement Sector comes in. The Greys have learned the hard way that humanity means trouble & so they've taken the opportunity to take it upon themselves to take the cybernetic & robotic technologies from the Clement sector. Why?!
The Greys have an interesting stragey for handling the 'human problem' and that is using medium, heavy duty, & light duty robotic life forms to man their bases. They keep the Greys safe & humanity on its toes. The SW11 Malingee Warbot is top of the line for giving mecha & walkers bloody noses. KAY9 Security and Guard Robot patrol Grey Science & Research bases. Cleaning robots monitor & keep the upkeep of Grey bases solid.
Meanwhile type 2 (TL13) AI Core biosynth's handle any interaction with humans & A.I. core life forms handle their own fleets of drone, war droids, and even walkers.
Whole arrays of drone war drones & vehicles can easily be designed using Moon Toad Design's Cepheus Engine Rpg Vehicle Design Guide. And since the door swings both ways so to speak the chances are that it is very unlikely that the Greys would put their numbers in harm's way with humanity & their toys. When the aliens themselves can also use humanity's weapons against itself.