I can offer some personal input; my brother just made LTC
recently, at age 37. He was a NSF commissioned officer, but didn't
sign on until after he ORD'd & have completed his NTU degree
course. It was interesting tracking his career; he wasn't a
shooting star by any means, but got promoted at roughly the "right"
stages. There's a underlying professional momentum affecting all
regulars, & the status perception is being "condemned" if they
don't attain a certain rank by a certain age (esp. prior to getting
the 1st crab.)
Finished OCS - 2LT
Before ORD - LTA
Mid-20s - CPT, usually with a command stint at the company level or
equivalent
29/30/31 years old - MAJ
Up to this rank, the promotions road is generally consistent &
predictable; a regular officer would also tend to finish his 1st
bond commitment by the end of this period. Thereafter, there's more
of a "politics" element that come into play, since there's only so
much available appointments for MAJ or higher, & a candidate
would have to compete with the scholars who're on the fast track.
It also takes place more in the staff-officer (not combat-) arena,
so your track record of requisite training courses is also a big
factor. My brother also used the opportunity around this stage to
finish a Master's degree in Public Policy.
As for Lee Hsien Loong - & also the other Big 4 military
scholars/politicians (George Yeo, Teo Chee Hean, Lim Hng Kiang, Lim
Swee Say) - I think their rapid SAF achievements have more to do
with the fact that Singapore was trying to create a professional
officer corps as quickly as possible from the early 70's onwards.
It's a credit to them that they didn't fail the test.
Prior to that, the pioneer officers were either remnants of the SVC
& SMF - 1SIR/2SIR (& national service in general) were
initiated with self-government in the late 50's, rather than
independence in '65 - or commissioned with the new SAFTI-trained
batch. The military in the early days was also PAP-controlled; flip
through the pages of the Singapore Artillery 100th Anniversary
book & you'll see Goh Keng Swee reviewing troops - in military
dress as a "Honorary Colonel"!
Thus, there's fast track for today's SAF scholars, & there's a
more-urgent fast track for their predecessors 2 decades ago. Here's
a link of that era's progressive batch: LHL was the launcher of the
program in '71; the other quartet were chosen 2 years later (though
it was TCH, being career naval officer, ended up as the least
politically experienced today).
http://www.scholar.mindef.gov.sg/ourscholars_succ_intro.asp
Even as all senior officers should complete a CO stint with a
combat unit at some point, those who are scholars aren't always
required to do this "linear-ly". In other words, they may be posted
to attend staff-officer courses (local & overseas) earlier in
their careers; the implication being MINDEF or the SAF taking a
long-term view of grooming. That's partly why the non-scholar
officers sometimes feel 2nd-class & shortchanged, after being
bypassed for promotion or reposting in favor of the high-fliers. So
much for meritocracy ~lol~