How realistic was the airplane scene in Terminator Dark Fate?
Completely and utterly ridiculous. Let me count the ways:

First video:
0:22 That collision would have destroyed the bigger plane as well, rendering the entire rest of the scene impossible.
0:35 As you mentioned, the wake turbulence would have knocked the trailing airplane down and away.
0:46 There's no way that collision lasted for that amount of time.
1:11 The autopilot would not have been able to function with that level of damage. It wouldn't have even attempted to activate.
1:19 The front of the plane isn't damaged, so the only wind would be from eddies from the hole in back. Which would be pretty strong, don't get me wrong, but not nearly strong enough to pick up a full-grown woman.
1:33 Gravity doesn't just "go away" when you lose two engines. Not to mention the wind described earlier would still be a factor.

Second video:
1:22 Having one parachute open would have slowed the fall of the Humvee quite a bit. It wouldn't still be in freefall.

Note that I'm only covering the aviation-related ridiculousnesses in that scene. There are quite a few other ways it fails basic physics as well.