I linked to the Lego video because it at least looked like a solid object hitting another solid object, unlike the shot in question. I mentioned the pyro because the pyro in the original shot was shit and had an obvious flaw. Both reinforce the point I was concurring with, the original shot was lousy and substandard compared to other work in the film.
Let me rephrase it in the form of a joke.
"The shot was bad."
"How bad was it?"
"It was so bad, some people screwing around with a toy and a high-speed camera for clicks addressed or avoided its two most obvious faults!"
Ha, ha, funny, we all laugh together at the absurd comment that holds a grain of truth.
If I am to evaluate the Lego shot in terms of how convincing a model it is of what a Super Star Destroyer crashing into a Death Star might look like, then I have to consider the premise that the most correct way to model the situation is as a ship assembled from Lego bricks being dropped onto a solid floor.
But, if our tools are Lego bricks, then that simply isn't the most correct way. The battle station itself has a composition similar to the spaceship. We know this, because we've seen the interiors of both.
Therefore, a more correct way would be to model the surface of the
Death Star II as itself composed of Lego bricks. Not only should the Super Star Destroyer break apart, but as it smashes into the surface, it should make a visible crater. You would even expect to see waves propagate away from the impact, pieces of the surface snapping off and flying up, perhaps some even quite a distance from the impact, especially given that the surface of the station isn't completely uniform. But especially you'd expect to see a mess of bricks breaking loose from the surface in the immediate vicinity of the impact.
In short, just as the ship will break apart, the surface of the station would react, and at least a portion of it will break apart as well. There will be more than enough kinetic energy in the Lego ship to unsnap bricks on the surface.
That said, I've no doubt that how many bricks get dislodged from the surface wall of bricks would depend upon the pattern of how they are snapped together, what type of bricks they are, and so forth. But you aren't allowed to devise a brick arrangement that results in the least number dislodged. The objective is to lay bricks to model the surface similarly to the way the ship is modeled. We've seen the surface, and we know there is a great variety of non-uniformity there, including gaps.
We also might reasonably imagine that the engine of the spacecraft is much denser than the habitable parts, and therefore also than the station surface that the spacecraft is smashing into. For greater fidelity, that needs to be modeled as well, as it would contribute to the effect of the ship "driving into" the surface.
