I'm also experimenting with the Arp right now.
I think the idea is not bad to copy the arp from track one and use it in track two.
I think it works either:
if the arp was created by random in which the array is copied and then used as array for arp 2 by button.
or
if the user creates the sliderpack himself - basically the same thing happens.
The array will be copied and inserted by button into another SliderPack (of Arp2) again.
So at least theoretically :-)
I will try it