Well, i really don't want to hijack or answering this kind of unconstructive question.
Basically transcient response definition is
Here, it's not entirely the length, material, drift velocity alone, but also temperature, gauge size, and capacitance.
In lay man term, a frequency response is sound energy vs frequency, transcient response is trascient speed versus frequency.
Whatever you "think" it is transcient resposne, it isn't. I think you mean drift velocity but I'm not sure, cause if you use two identicle cable, material ,gauge size and length, same shielding and outer dimeter, it will be the same.
Hence I donno what you're trying to pointing out, at all.