WHy would they not issue you a class 3? As mentioned, as of now,
you can convert a foreign license to Class 3 after passing the
Theory Test.
The requirements are simple,
a) have a foreign license,
b) have an extract from the authorities that you have been driving
for more than 1 year and that you were never banned from
driving.
c) Have a valid reason to be overseas (studying, working, etc).
This is to prevent people from going overseas just to pass a
driving test. Usually evidence needed are, School results, Exit
Permits, Visas issued, etc.
d) pass theory test
To your 2nd question, Nope. If you are suitable for a combat
vocation, you are more likely to go there than being a driver.
Having a license has no impact on your vocation because SAF has
their own driving standards which you have to pass anyway.
And they will only take into account your license only if you have
the Singapore one. The only "privilege" you will get is that you
only need to take the SAF's driving test without going thru the
course to be allowed to drive the Land Rovers.
However, i advice you against this, since it just takes the
inconvenience away from your superior officers from indenting a
driver everytime, you will be his driver instead. And trust me,
it's a 4am to 1am job during exercises.