[mst]

Are you trying to confuse me?   

Not intentionally

If the aperture is f/2.8 and the shutter speed of two systems is the same, ISO will also be the same

Yes, but that's not what we're talking about. It's about creating the same result with two different systems, and that means comparing images created with equivalent, not same settings.

Your point was: you can shoot with f/2.8 on m43 and thus have faster shutter speed compared to shooting with a f/5.6 lens with equivalent focal length on a full frame camera.

My point was: you're ignoring ISO, because on the full frame camera (assuming similar resolution and sensor on roughly the same engineering level), you just bump up ISO by two stops, because that will lead to the same image quality in terms of noise and result in the same shutter speed, too.

In other words: there is no speed advantage of a 200/2.8 on m43 over a 400/5.6 on full frame.