No, not exactly but the full details are way more complicated.
The LM1084 has a high voltage drop - which means many PC's will not run off it's output since the car voltage - the voltage drop is too much. You probably won't be able to combine them straight with the ITPS since the ITPS with it's extra hardware will likely have a different voltage drop and hence either it, or the LM1084's will end up trying to dominate.
Search for my thread on using 15 2A regulators in parallel into a PW-200. It's cheaper and they have a much lower voltage drop. That's how I'm doing it. Cut out the ITPS and it's way cheaper but you have no automatic shutdown controller. But you can build your own very cheaply or buy zootjeff's which is fairly cheap.