You cannot. You already know how to determine how they are instantaneously, beyond that, there are no guarantees. Routes are often determined by latency, throughput and so on, but they're also affected by accountants and politicians. If you think a route is wrong, it could be - try reporting it.

I don't think 'therefore' is quite right here! The lowest latency you'll get for your Malaysia market will certainly be from a Malaysian server. Physics says so. It's well known that the speed of light can vary greatly in the vicinity of accountants and politicians, so you just need to choose your location with care. More of what you're already doing is probably the best bet, tried from various locations around Malaysia. There ought to be a website where you can get those stats...

Low latency - are you intending to put up a game server? Please put Tremulous on it if so. I'm fed up with being pwnt by n00bs who think they're godlike, just because they're in an Internet cafe in the same US city centre as the server. I must get some work done.