That's garbage. My brother (I'm Australian) is
Alexander (he's twenty-eight), and his nickname is Zand (same as Xand or
Xander really). Additionally I have met several little boys named
Xander in my travels through music / playgroups / dance / school.
If you were spelling is
Aleksandr or something I'd say, hmm, maybe that's a bit awkward, but
Alexander is a fine, handsome name for an Austalian!