So you believe the spear should be just a tad shorter than Kal-El? That's sort of what I was thinking. Right now I have the staff scaled up to be almost 2 inches taller than it is, which should put it right around shoulder height, then add the height of the spear to reach about halfway up his head/neck.
That's the plan! Probably getting a new print ordered tonight or tomorrow. I'll have BvS Kal-El delivered next week, it seems, so I'll see how it compares to him, let alone MoS Kal-El.
The best reference would be the scene where he slams the spear into the ground, but I can't seem to find that
Here is the whole scene where he fights Supes with it: https://www.youtube.com/watch?v=IWH5rQ23T7c
Tough to gauge there but it's pretty fricken long, I feel like when he slammed the kryptonite into the ground, it was still almost as tall as him