I don’t know much about modeling but this game got me interested because of it’s feature to allow, for custom models so I decide to try, and follow Josh W tutorial on making custom models, and i have made some progress on the model from the picture, the only problem is that it’s deformed, and for anyone wondering I already did the rotation, and scale part
Some of the vertexes are missing bone weights, look for parts of the model that stretches to the origin point (0, 0, 0). Apply bone weight to those vertexes.
When you import your model over the skeleton, you will have this small center circle that has to allign with at the center of the skeleton (at its feet)
I don’t know if that is the answer you are looking for, but good luck 