I’m not too sure the scans are the same, as with AP in the aircraft is being controlled through the MCP/FMC, which necessarily takes attention away from instrument monitoring. Most SOPs are when the PF is hand-flying, the PM will look after all the selections so the PF can concentrate on the instruments?
Every approach has a speed, flight path and ROD. When PF is hand flying how will he ensure this without scanning? On approch in Airbus the ATHR has to be in speed mode with hand on thrust levers. What's confusing about it? Yes it's possible to be distracted but not till 25/31kts below Vapp. And what happened to stabilized approach idea? This wasn't a check of 250hrs CPL. What happened to tactile feed back of Boeing throttles? They were stuck at idle throughout. In these two cases aircraft had no problems. In London B777 case the aircraft had a problem of fuel system ice crystal contamination case but the crew noticed everything, the throttles stuck, thrust not sufficient they even pushed them but were not in position to do anything. Scanning is essential.