dan
2
Hi Wally and welcome to the community 
Your first hypothetical setup seems to be Wet (mono) Dry. For a Wet-Dry-Wet you need three power amps; there is no other way around it.
Take a look at this video,
There was also a recent discussion about this here, that used one Power Station,
Hope that helps; let me know what you think, and we can take it from there.
Regards,
Dan