Sarcasm noted. That being said, when it comes to ruthlessness, Black and Latino gangs are pikers compared to Asian (and Russian) gangs.
What is surprising about this story is that it appears the victims were not Asians. Asian gangs almost always prey on their own.
Based on my experiences living in Brooklyn and Seattle, you are correct. There were several cases in recent memory in which (specifically) Chinese immigrants were brutally murdered in home invasions, dismembered bodies and all. In cases where the perps were caught, they were associated with criminal Tongs.
The Albanians are pretty brutal too. Its one thing to shoot a man dead, quite another to often castrate him and leave him dead with said member in his mouth.
Asian and Russians don't really have gangs (although Oriental Boyz is a gang in the L.A. tradition) they're mostly organized crime groups who may have some influence by gangs, such as being taxed by the homies if you know what I mean.
Just look at who is locked up and who does what and then you'll see who is ruthless. I only say this so that you get a better grasp of reality and your surroundings cuz what you said contradicts what I know.