I’m here to do some unpaid work for the clever folk working on this DLC.
Since you’re dead set on releasing the Ballista Elephant with such a slightly altered existing Springald model plastered on top of it, here is a suggestion that will make it look infinitely better, at least from other angles than straight top down.
From what I understand, the developers put on the task to make these unique units have effectively no resources to work with but existing assets of which they are either retexturing or very, very slightly changing, while keeping the overall topology and skinned skeletons.
Notice how the “ballista” is just kind of floating there, with the ropes hanging onto nothing?
The ropes are meant to be supporting the Tower Elephant’s Tower. So the suggestion is very simple, actually. In the model where you have plastered the Springald model, you have decided to remove the entire Tower.
My suggestion is thus; keep the Tower, but manipulate the textures to make the upper walled portions of the Tower see-through. The result will be that you will have the Tower’s foundational platform without its walls, of which the Springald model will then be neatly placed ontop. While you’re at it, you could also make the two cylindrical sticks at the bottom invisible on the Springald model, as they have no function (no wheels).
The ropes, belonging to said Tower platform will have something to hold on to, giving it all an actual functional appearance, with a support structure that is actually built to fit the elephant’s back instead of being a flat platform on a rounded back. While this type of Ballista never existed, let’s not get so lazy where we are literally placing floating assets on top of each other. Frankly, it’s an embarrassment that the bar is so low.