Why are there only two coil control pints in my ECM?

[Ajax]

Hi! So, I was studying the pinout of my ECM, and it looks something like this:
pinout 1.png
pinout 2.png
As you can see, there are two similar set of pins. One set controls ignition for coils 2 and 3 and the other for coils 1 and 4.

I have a single coil system, so I assume those pins control the spark plugs directly by sending a signal to the coil.

My question is, why are there two sets of pins that control the same instead of 4 pins (one for each spark plug)?

Are two spark plugs firing at the same time? Do those pins onyl control timing, and the firing is directed by a different circuit?

Thanks in advance for any help you can provide.

[gtstorey]

How about some info on what you are actually working on?

[Ajax]

How about some info on what you are actually working on?

I'm not really working on anything, I'm just looking at the pinout and trying to make sense of it. It's a Chevrolet Aveo T250.