One "flight director"
As a regular flyer, in the last, say, 3 years, I have not been on a flight requiring major pilot flying intervention. I mean failed engine, plane divert, go-around, etc. However, I have seen the pilot out of the cockpit 3 times to sort out unruly or distressed passengers.
I'm confident that autopilot and AI can fly a plane better in emergencies than some of the less experienced pilots.
So I see the pilot as being the director of the flight who can also assist in the cabin when the plane is in normal cruise. That gets the cost saving that the airlines demand.
2x pilots, 1x Cabin Director, 2x stewards becomes 1x Flight Director, 2/3 x stewards
And, if at 30,000 feet the engine fails, the autopilot will take care of the shutdown in the minute it takes to get back to the pilots seat.
Maybe we will start with a "rule" that cockpits only need to be manned below 10,000 ft?