Oh dear, its quite cynical
 

It seems this 'Ziggy' character has only adopted that name recently. Is this not a rather cynical attepmt to sound 'cool'?

Quite frankly, its pathetic, rather like the 'Action Man'-faced fool.

It brings to mind... http://www.5years.com/image19t.jpg

I was wondering if the reason though they used his nickname was that there is another 'Zac' due to come in later.

^ Oh, that's a possibility! Hadn't occurred to me.
I just assumed that's his day-to-day name and what he's known as these days by everyone, so it makes sense that's how he'd present himself really. Whether it's a pathetic name or not I've not given a lot of thought to.