I have no first hand knowledge of the Airbus since I worked for Boeing. So I can't definitively state how the A320 works. But all the Boeing installations work the same way - the FADEC channel alternates every engine start, assuming equal channel health (note one minor exception, some installations won't alternate channels if the previous engine run didn't go above idle), and each channel alternates igniters every engine start. So while the channels alternate every start, the igniters alternate every other start. To do otherwise would mean that each channel would end up using the same igniter every time, and a fault in one channels ability to use an igniter could go undetected indefinitely.
BTW, on Boeing installations, there is no flight deck indication of the igniter being used.