Yea I think you're right. I had to read up on it. Found it on Carls site. But citrix Site i haven't looked yet. I believe this is it!?
“If you configured farm aggregation without load balancing, then use the up and down arrow buttons to put the active site/farm for this group of users on top. The lower priority sites will only be accessed if the primary site is down. You can run this wizard multiple times to specify different active sites for different users.”
“If farm aggregation is configured for load balancing, then there are no arrows to prioritize the farms.”
https://www.carlstalhood.com/storefront-cr-configuration-for-citrix-gateway/#gslb