One should not forget that those "procedures" have a great influence in the air combat!!!!
If one doesn't follow the procedures in i.e. the engine handling one will pay for it big time in power loss!
What is a spit or a 109 with 500hp? right, a sitting duck waiting to be shot at.
The engine start up is a procedure that always is the same, with very minor modifications.
There is no reason not to put it on 1 key and the switches and handles are moved automatically, but manually one should be just a bit faster doing it
Also the procedures in the stuka for the dive attack, cooler closed (engine stays warm!), prop pitch to "feather"(no over rpm), trim to neutral (straight dive), "Hoehenlader" to "Bodenlader" (no manifold overpressure), release altitude set, dive brakes out.
Just one thing missed and one won't be on target or gets problems getting away.