I don’t think there are key criteria for guaranteeing a connecting flight. If your incoming flight is delayed, the onward flight will go without you and you will be re-booked on the next available flight.
Twice when the plane has been late incoming Swiss had a car waiting at the aircraft which has whisked me (and two other pax) to the outgoing plane for direct boarding. The only problem with this, at Zurich anyway, is if the connecting flight is to NY or London, you have to go through extra border / security controls and then you will miss the onward flight as has also happened to me.
The only exception is if a large number of people on the incoming flight are also booked to go on the outgoing flight, then they will usually wait, but of course you won’t know if that is the case or not.
All this assumes you are through checked of course, and that is the main criteria, as you will then hold the relevant boarding passes.
I have never had a problem with onward connections being rebooked, hotel accommodation if applicable, transport to / from hotel and meals, but I have been in the premium cabins when this happened.