Linking equity to performance and financial benchmarks creates
BS, it does not eliminate it.
Imagine you had a regular job. Each pay period your boss sat you down and said, "I've reviewed your performance and financial benchmarks and I'm not super happy so I'm going to pay you less than last week."
In order for that meeting to not turn into a major fight you would have to have EXTREMELY clear performance and financial benchmarks that were entirely under your control. Try getting this kind of clarity at a startup company (not going to happen).
You can certainly fire poor performers and people who don't meet financial goals, but trying to compensate them like this is a nightmare.
As I said before, use Slicing Pie, it will do 100% of what you need your equity program to do.