Hence the problem. It results in The Crabator, unnecessary, widely unappealing changes to the fictional character's inherent design.
So, the problem comes from not sculpting the mouth to close to begin with-
I wonder then is that a choice ADI made or it just so happens to be a choice;
Paul Anderson, The Strause Bros and Shane Black all made.
Anderson wanted more "heroic", handsome-looking Predators, so the mandibles became marginalised. With AvPR they wanted to make the most of the fact they didn't need to use the actor's eyes and created a very differently shaped head. The Predator, eh, probably used to it by now and nobody said to do otherwise.
Then you've got KNB- that got the "X" correct,
The "x" is only for certain cases. The original doesn't actually make much of an "X", more of a T or Y shape. The lower mandibles aim relatively straight up, and the upper mandibles either sit across or with a slight downward turn.
The lower mandibles aim in a bit, but it's not an X.
I should specific "T or Y at rest"...