@Shambala108 both are organisations which have appeared in Crossovers with these series Blake’s 7 pretty clearly happens in the Universe thanks to the Kaldor City audios and the Alien franchise also works in universe thanks to several minor crossovers on screen (such as in Paradise Towers and the animated version of Power of the Daleks as seen in the picture, the ChestBurster itself appeared in Mindwarp) including significant suggestion that the Xenomophs also exist and killed JFK during the War in Heaven (of course this being a major battle in the war in Heaven no one is quite sure who finally pulled the trigger.) and are a possibility for the identity of the enemy,