This really seems like a case of trying to compare two arbitrary metrics and look for correlation. The thing about HDL is it is not code in a traditional sense, it is not instructions being executed, it is a description of a circuit. The thing about descriptions is that there are so many ways one can describe the same thing that you could end up with hundreds of pages or just a few sentences, both accurately describing the same thing. For example if you want to describe a cube drawn on a piece of paper you could just say there's a cube drawn on a piece of paper of this size originating at whatever coordinates, or you could say there's a line drawn from this point to that point and another line drawn from another set of coordinates and so on. Both are perfectly valid methods of describing the drawing but from different abstraction layers with vastly different length of description. There are many, many different ways of describing the same circuit, and there is not always one correct way.
Lines of code in general is not a very useful metric, but is even less meaningful with HDL than with a procedural languages.