Mr de niro, l am afraid l have been out too long to offer any specific info regarding the paperwork involved in the initial recruiting process.
l would be inclined to telephone or pop into the ACIO and ask for a more detailed explanation. The staff should be only too willing to bend over backwards and explain the situation as it currently stands . Afterall it is thier job to make the process as smooth and easy as possible.
The more technical and specialized trades and jobs do take a bit longer to get in as there aren't as many courses each year.
Edited to add , Army Rumour Service (ARRSE) is a good source of info, there are threads specifically geared to the recruiting process that are worth searching out.
Whatever you do don't ask serious questions in the Naafi Bar forum section, as anyone who does gets ripped to shreds.
l saw a few of the usual suspects piping up with negative comments regarding the Army, basically they don't know thier arse from thier elbow, l did twelve years and it equipped me to tackle any challenge life throws at me, l wish l could do it all again.
My own son will be going in after Uni .
l wish your lad well, it will be the making of him.