The team with lesser idiots wins
. This syndrome affects all new multiplayer titles featuring 5v5 or 6v6 games. Even if 1 guy is bad, that's a gigantic 20% handicap on the entire team.
TF2 doesn't suffer from this with its 12v12 system. I never ever felt frustrated in TF2 because of bad team comps and that game didn't even have a matchmaker when I used to play it.
On the topic of server regions: If you want to play on SEA Singapore servers (as you should from India), then you have to play on Americas.
The way that Blizzard has divided the zones, they have put SEA in Americas. If you select Asia, you will end up on Chinese servers afaik.
Diablo 3 is an exception as that game's Singapore server lies in Asian region.
If you select Americas there, you'll actually end up in an American server with 300ms. Not that it matters because that game is PvE and has a great netcode where 300ms feels almost like a local game (provided you have a stable Internet connection of course).