I did a quick calculation for estimated margin usage, based on 50:1 leverage. Using $300/0.1 lot as my safe reference, a person should be able to safely use 0.2 lot with a $10k account. Assuming all 12 allowed positions are open concurrently, the margin usage would be $7200. This leaves plenty of room for all trades to go to stoploss without coming close to a margin call.
Make losses, but always come out a winner at the end.