Not the way you have it drawn. I may be wrong, but you've effectively created a USB Y cable and that pretty much violates the USB standards.
What are you trying to do? On initial glance, it looks like you're trying to make a CP that's compatible with either the Xbox or 360, but why hack off the Xbox cable and replace it with a USB cable? That leaves you with a controller that's kind of useless on the Xbox and is pointless for anything else due to the existence of the 360 controller. You can keep the existing connector with some minor modifications. With the proprietary xbox jack, no one will mistakenly plug it into the 360.
As for the connections between the two controllers, I don't know. The answer is a wash due to the USB splice you drew up.
I'm not trying to be an ass, but if you tell us what your goal is, any number of us can offer you a solution that might fit your needs better.