The original scale is pretty much useless for vanilla defense attributes. It lists increments of 160 up to 1120. The vanilla battleship has 3000 hit points, so it takes 1500 to crash it. You have to push your defense bar pretty close to the end of the page in order to even start to have a chance of shooting the ship down, and that's assuming nothing misses. But even the vanilla fusion defense singlehandedly fills the entire bar.
Has anyone else thought about this? Is there a way I could change the scaling? I can doodle on the background image if necessary. I'm thinking a good set of numbers should be increments of 1000, with the final increment reading 7000. In original vanilla attributes, a base defense value of ~3000 is ideal to have a decent chance of shooting down a battleship. Or I could see reason to go a bit further and multiply the increments by 10, raising them to 1600, with the final number reading 11200. At that scale, there's room for even larger ships with more hit points, meanwhile even the missile defense at 500 will show at least a few pixels on the chart.
I think to change this, we need to change both the background image as well as the code determining how it scales. The first one of those is probably by far the easiest.