Finally i could make an arrangement to play mission 3 regularly with either two or three Aliens but the third will never show up much as the one of original M3 does, it will be a complete new and hard experience to deal permanently with Aliens in an area where you had not many encounters before. As you might know you will have no effective tools to tackle them at this stage but i can give you the motion tracker for a better chance to survive. I will make the complete mod guide soon, so stay tuned and take care.