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.
Who's locked up does not always constitute ruthlessness. Because drug charges carry such high penalties, most prisons are filled with drug cases and most of them are for selling drugs not killing people because of drugs.
Also, many Hispanics, Asians, and Russians flee after they have committed a crime. You need to get a better grasp on what's happening in the world. I think many posters have given you an idea of what is meant by true ruthlessness.