this is mostly due to convenience - our name tags have the
initials of our first names, and our surname, so naturally, A B TAN
will be called Tan, which sounds more suitable than calling the
person A B rite? but of course, some of us have more unique name
tags with only christian names and such.
Actually, calling by surname is also informal as far as the
military is concerned; it's the same culture for foreign armed
forces. Remember the "Tour of Duty" TV series? The enlisted
characters called each other "Taylor", "Purcell", "Horn" (the RTO),
"Johnson", et al.
As for calling by full name - presumably for only Chinese - IMO
it's no different than how the Koreans, Taiwanese or PLA Army
troops address each other, even with buddies. It's part of the
general Oriental accent: an underlying self-awareness that many
hailed from different parts of the country, & thus politesse is
accentuated as they began to train together. It's the same with the
S'pore context, less so geographically but the initial
unfamiliarity is still there (the contemporary "connectivity"
within the island only came with the MRT system).
Wait till you reach reservist. My own experience was that even the
men-officers were on a surname basis - at most, they'd address the
junior officers by their appointment or, more generically, by rank
("El-Tee"). The senior officers were addressed mostly by
appointment, sometimes funnily like the MO being nicknamed "The
Doctor" cuz no self-respecting LTA was willing to acknowledge his
CPT rank! Only the CO was regularly addressed as "sir", except by
his driver who called him by surname!
