In reading about fuel injection, I remember some info about batch fire vs. sequential fire injectors. The batch fire stuff (including Tuned Port Injection) was far superior to the Throttle Body Injection (per Fuel Injection Specialties web page, the improvement was on the order of 30% in torque).

The sequential injection is theoretically better since the timing of the pulse can be tailored for each port.

For your question (as I think you are asking), the batch fire sequence really doesnt matter because the intake air flow is not coming to a stop....it is continuous, especially at higher rpm. If the injected fuel is atomized, it mixes with the air fairly well.... certainly better than it does in a carburetor.

When the OBDII standard arrived with all its additional checking and the new emissions standards, sequential injection offered a tad more precise control.....mainly for emissions.

So.....to answer your question.....it doesnt matter. AND, they chose to fire banks because the wiring was mucho simplified as opposed to having two circuits on each bank....saved them a few pesos.