Triple picking is putting your 123 picks in and around one bonus intending to take it fast. It is bad because you aren't able to expand very quickly after the initial boost you *sometimes* get from taking your first bonus a turn fast. In your game with dodo commander your income grew in line with his. Having your bonuses packed together means once one is broken the others follow shortly after so you can't simply sacrifice a bonus and go on the attack somewhere else (like dodo commander did). You also are easily counter picked especially if your opponent gets one of your top 3 picks.
I speak from experience,
http://warlight.net/MultiPlayer?GameID=3204156
Show me an example of a good player attacking 5v2 in the early rounds and I'll be more specific but it's to ensure they have lots of armies in the right place for the start of the next turn and their next turn's deployment is more flexible.
In ladder settings you can't lose a 4v2.