A:Answer The official ASUS answer is incorrect even at what they are trying to say. Its not a USB-C cable that can connect between the dock and the system. Its a 65w USB-C to power block, and the USB-C cannot disconnect from the power block and be a cord on its own.
The power supply provided with the Xbox Ally X cannot be used with this. You will need a separate 100w supply, which ASUS charges over $100 for. So you're looking at $250-300 for the dock and power supply.