Seems like there's a glaring loophole there. Let's say they want to pay their top five people ten million dollars each. And let's say they can think of five VP-level people who should be earning around $500K each. Why not say "Oh, these VPs are crucial to our survival. They're worth $20 million a year. Sadly, we can only pay them $500K of that." At that point, the VPs get about what they would normally get, and the traders can safely be paid $10 million a year.
I guess it depends on the final drafting. Drafting the cap as "top 5 highest paid people can't make more than $500k" should solve the loophole you just wrote about.
If you sort employees by pay it is the same. But if you sort employees by power it might not be.
For example, some sales people at tech companies make much more money than mid-level managers taking home a couple hundred thousand dollars per year. Some of those sales people will make more than the senior level executives. Which one is more important and is higher rank is up for debate.
In my comment above I tried to explain a way to fix the loophole that byrneseyeview listed. Saying nobody makes more than $500k is a way to fix that.
Or am I misunderstanding the cap?