Originally Posted by
thatmikereed
Separate tickets on the same carrier or different carriers?
It doesn't really make a difference to be honest (for the reasons you rightly mention in the second part of your answer). If you book, say, FCO-LHR-LAX on BA and book a separate LHR-FCO to get to Rome, it is delay and you miss your FCO-LHR departure as a result, you'll lose your flight whether you booked that LHR-FCO with BA, AZ or any other.