Firewall sandwich

Sorry, last two issues. 1. According to my test when Auto Last Hop is enabled even if there is no DG defined at all on BIG-IP returning traffic is correctly directed to original last hop. So why at all define GW pool in original schema from LB101? 2. In some answer to LHP question there was info that Auto Last Hop nad LHP are excluding each other. Looking at the https://support.f5.com/kb/en-us/solutions/public/8000/200/sol8290.html it seems not true. As far as I understand when ALH is enabled along LHP then ALH is responsible for returning traffic to the same member in LHP that original send it. I can't really figure out what will happen with ALH disabled - how traffic will be returned to correct member. It seems to me that LHP is only prohibiting returning traffic to MAC that is not belonging to any of members. Still description in sol8290 is a bit cryptic to me so I could be wrong here. Looking on schema in LB101 I wonder how traffic can be returned to FW in the GW pool that originally send it (if ALH is not enabled), in this case packet will be sent to member only according to LB used for GW pool? Piotr