Although the achievement says you have to play ranked matches to get it, you don't. I got this in unranked party matches, and have helped friends get it.
Set up a Strong Arm match for one of the seven required activities (Theft, Snatch, Demo Derby, Racing, Mayhem, Insurance Fraud and Hitman). Rotate the wins over the seven activities so everyone involved has won each one, then move on to the next activity and repeat until all seven have been won by all playing.
Then simply play a game on each of the seven Strong Arm maps (Little Shanghai, North Shore, Nuke Plant, Oldtown, Parthenon, Posiedon's Palace and Wharfside) to unlock the achievement. Be sure to let the other people you are playing with win on each map before moving on to the next one to save time.
It's worth keeping a pen and paper handy to keep track of what you have done to make it easier for all involved.