Numerous small losses added together equal big losses. When you trade for the big picture you have more positive expectation in terms of the move. The larger the move, the larger the validation of the move. If you were trading some short term pattern predictive system you would never be able to participate fully in the big trends. And big trends make the big profits.
All systems have drawdowns.
You can't have a profitable methodology, without having some risk and taking some losses. Turtle drawdowns are a function of risk level desired. Risk level among Turtles varies depending upon the reward sought. More on Turtle Volatility . A. Required margin has little to do with money management considerations.