No more dicky than the rest of them.
The Commonwealth Railways used an Alpha Numero system
from the outset, eg: their first standard gauge loco's
were classified D they were the NSW Q class.!
Their "first" narrow gauge loco was the little Baldwin
0-4-0 Sandfly which became NA1.
Hardly surprising since the Chief Engineer of the
Commonwealth Railways was one Norris Bell who later
became the first CR Commissioner and along with his
able assistant George Hobler came from the Queensland
Railways.
As long as the system was able to work with the
classifications, which they did, who gives a stuff.
----Tell
Alice Springs NT