I think serveral of us have already answered that. Posts 13, 15 and 16 for example.
Personally I feel it better to be level with the tunnel able to watch the offside line, rather than the other way around. It seems preferable to give priority to the primary concern (the scrum) and keep and eye on the secondary issue (the attacking side possibly reducing their own attacking space.) But, of course, we are all different.
That goes without saying!
Didds asked so I thought Id have ago to help. Sorry if that wasted your time and seems to have upset you.
I ve mentioned more than once Im happy with the tunnel position when there is comms. As the AR can be effective when there is an offence. Without comms there's little you can do to assist with the scrum (except foul play maybe) even if it is a primary issue you can do no more at the tunnel than you can 5m back.
Without comms, marking the attacking 5 has the added value of just being there then the back line can see you and you can keep them honest. You can even talk to the winger to get them to manage their team to be onside.
I think this is one of those horses for courses things and not going to die in a ditch over it.
I know I said a very obvious thing about observation skills, it wasn't trying to be condescending, unlike your retort it seems, but it was merely to reinforce that the near side AR positioning isnt the most critical factor to managing the scrum. That obviously went over your head.