Kinda a day late, but let me add something to the discussion.

There are leftover animation for the rocket launcher from XCom: EU within the files. They are rigged with a different biped from XCOM 2, I mean very different from XCOM 2's biped. You would have to spend days reanimating every animation to XCOM 2's human biped just to get it to work with XCOM 2. Believe me, I tried.

If you're trying to replace X2's Sectoid with EU's Sectoid, it won't work because of the problem listed above. You would need to export all of X2 Sectoid's animation, reposition the bones of the imported animation to the EU Sectoid, and hope that it doesn't break the animation.

The other way is just to import the animations of the EU Sectoid to XCom 2, and make a brand new enemy that points to the new animation. Not sure if it this is the most feasable way, but it doesn't hurt to try.

Edited by E3245, 21 April 2016 - 06:00 AM.