When I was at primary school we had scripture lessons. I learned that Moses had an older brother whose name was Aaron. It was pronounced with a long 'a', because there are two 'a's there and it sounded more or less like this - 'air-on'.
For decades I have heard and seen people being called Aaron - spelled like that with the two 'a's at the beginning, but pronounced 'Arron', more or less rhyming with Karen, Darren et cetera.
If a parent wants a child's name to sound like 'Arron', why do they spell it/have them baptised 'Aaron'?