No, what you're referring to is called the mono intake. All the
SAF frontline units (SIR, SAR, SA, GDS, CDO, SCE) muster their
fighting troops this way, & these guys stay together from BMT
right through reservist, forming the main body of the unit. The
Tekong trainees will join the unit only after their commander (OCS,
SISPEC) or vocational courses (signals, medics, drivers, storemen,
etc.) courses.
BTW This system was one of the reasons why Malays were excluded
when NS was first implemented, cuz it was more practical to staff
all the Hokkien peng (the majority of each intake) together for
combat duty instead. That the NSF "segregation" endures to this day
was partly cuz the Malays consequently built a solid legacy in the
Police & SCDF -- "if aint broke, dont fix it -- although,
with improving academic qualifications, they can also be posted to
the combat side (as officers & specs) now.
Armour peng traditionally quite garang. Dunno if they still do it
now, but once upon a time only they & OCS conduct boxing as a
PT activity! Also, before the SAF restructurings, there used to be
a big rivalry between the SAR & SIR formations (i.e. "heavy
(mechanized) infantry" vs. "light/line infantry") in the old
days.