That’s crazy, 5A/5V is not and has never been in range of the USB power delivery spec. It only goes to 5 amps at 20V for the 100W output, or higher voltages in the newer Extended Power Range topping out at 5A/48V.
Keep in mind at least 2A of that is to power the four USB ports at their rated 500mA. So if you don't have four USB devices loading the USB ports at their max, you should be fine with 3A.
5A/5V what are they smoking?