Are those numbers right???
The inner planet is 160AU and the outer 320AU???
For comparison, Jupiter is only 5AU from the Sun, Neptune is 30AU, Pluto at its furthest is only 49AU, heck the Heliopause kicks in at 123AU.
And this young Sun has two gas giants in its system massively beyond its Heliopause? There's not perhaps been an extra 0 mistakenly added on the end of those numbers, perhaps?