I think you're on the money about the SE making it worse. I think I know why it's weird to me.

The distance between them is actually more than the action suggests. (I've even gone over the shot with an actual DoP working in the industry). Look at the distance between Luke and the background and compare the depth of field, and notice how it has pretty deep focus, but then if the Wampa (who is OOF) is close to Luke as the action/cut suggest, then it would imply shallow depth of field which contradicts the background. So that means either the background is a matte painting - which it isn't in this shot - or that they cheated the Wampa closer to the camera (remember, a rule of thumb when shooting cinematic is to get the camera as far away from the action as possible and using a long prime lens to punch in closer) to make it look bigger, but ends up blurring it a bit.

So I guess in one sense it works, that in cheating the Wampa closer it makes him look to the correct scale, but if you notice the focal point vs background and foreground, the distance becomes more apparent.

I guess that means you won't be touching it. Thanks for answering my question!