Put it this way, Indonesia has a population of more than
200million, their defence budget is 3billion USD. Singapore has a
population of 4.4million, our defence budget is 6billion USD. If
Singaporeans are as you said, so unmotivated to defend our home
despite having much higher pay and technological superiority, but
are the chances are that our aggressors would stay in their
units?
But they're a professional army. Not citizen soldiers liks
us.
Instead, I'll rebut it this way: Indonesia is a big country, but
their armed forces is relatively small, supposedly only 300,000.
Their command structure is also regional-based (KODAM II is nearest
to us though, if I recall correctly, there are 3 other KODAM
entities stationed elsewhere in Sumatra) & their whole ORBAT
still centered around counterinsurgency ops. Their naval fleet
cannot do a Normandy-style invasion yet, maybe for the next 20
years unless there's an arms race in SE Asia.