That's exactly why they aren't easier to go from one to another.
Airbus has made a product that if you were only in the cockpit of the A318,319,320,330,340 the first difference would be the amount of thrust levers and the second would be the overhead panels. Look at a 737NG panel compared to the 757 panel compared to the 747-400 panel compared to the 777 no commonality at all (like you mentioned). However from the A318 to the A340-600 the only difference are the expanded systems, # of thrust levers, and nowadays the new LCD screens.
My previous post about transitioning to the T7 was not interpreted correctly. EY has the T73ER and I was only suggesting that it would have been 'easier' for someone to go from Boeing's 737 to 777
In addition besides the fact that everything on all the panels of airbus a/c stay in the same place regardless of model (unlike boeing). The flying stays the same, on T/O put the throttles full to ToGA and when your promted, (at a certain altitude, usually 1500 in the baby buses) bring the levers back a "click" to THR CLB and you have your auto throttle set for the whole flight until you take over to fly the approach.
Isn't the flying the same on any modern jetliner? Sounds like the same procedure I would use if I were flying a 727 or an A380? In addition, thrust reduction altitude is dependent on several facors such as:
Noise Abatement
Company policy
Terrain
EO performance
I will admit that the commonality on the airbus is a big plus. But as far as I am concern, most/all modern aircraft are flown the same way:
1.PROGRAM
2.SET
3.VERIFY
4.EXECUTE!!
5.MONITOR
Happy flying!
Bradda G