he idea with a humanoid-like aliens with armor and blasters (technically, it would be a native life form as this is a colony planet terraformed by future humanity
) may bring a whole new level of challange in the game.
Would be nice or something like this:

They could move at band at night like an offen event, damage constructions and doing some damage to weak wall too, like wood. Allien = fast speedy and acid attack (maybe 1 especial range attack with delay and the rest melee)
That new factions would attack animals too?
Humanoid-like aliens would be nice like a third faction doing a heavy defence at some ruins + good loot.
Just some ideias, but any plus challenge will be incredible.