The reason the Alien AI in the game is broken is due to a one letter spelling error in the game's .ini file. The line is written as

"ClassRemapping=PecanGame.PecanSeqAct_AttachXenoToTether -> PecanGame.PecanSeqAct_AttachPawnToTeather"

when it should read;

"ClassRemapping=PecanGame.PecanSeqAct_AttachXenoToTether -> PecanGame.PecanSeqAct_AttachPawnToTether"

Removing the letter A from this line fixes many of the issues with the game's AI.
Contributed by Mass Distraction