IMVHO the long slow poke one at a time is just good airmanship (airpersonship?) on any type.
The type of pilot that stabs quickly at buttons is also the type of pilot who doesn’t check the relevant system responds as requested. Thinking of the stages of error trapping, (Avoid, trap, mitigate), the button stabber will almost certainly be operating at the lowest level, mitigate. They’ll need ECAM / EICAS to tell them there’s a problem or will notice an issue after a period of time. The long slow poke followed by checking things are as expected (eg 1st pack on after t/o, feel the air volume entering the flight deck increase, then second pack on, same again) allows the person to operate at “trap” continuously and “avoid” if the slower actions prevent a mis selection.
The crew that is operating at the higher end of error trapping is also operating at the higher level of Situational Awareness. The levels of SA are Notice, Understand, Think Ahead (NUTA). If you correlate SA to error trapping, NOTICE = MITIGATE. UNDERSTAND = TRAP. THINK AHEAD = AVOID.
The crews who slow down and make singular selections are more likely to be operating at avoid/think ahead level which reduces their workload, avoids errors and allows them to maintain good SA, a positive feedback loop. They’re the crews most likely to have a calm, unrushed sector with a positive outcome (sim and flight).
The crews that make multiple rushed selections are more likely to make mistakes, forcing them to mitigate, upping their workload, causing them to rush, make more mistakes, mitigate again etc. a negative feedback loop. This is the crew that a sim check unravels quickly or has an incident on the line.
A calm, deliberate single selection at a time is a far more desirable behaviour than quick jabbing at buttons.
All IMVHO.
LD