When the angle of attack of a wing exceeds a critical value, about 12 deg, the flow across the top surface of the wing separates and lift drops a lot - the wing stalls. This separation doesn't happen uniformly along the span. On many tapered wings the wing is more ready to separate near the tips than near the root. In the real world one wing tip will go first, loses lift , drops and the fun begins. Dropping flaps on the root half of the span increases the camber of that section, increases the effective angle of attack relative to the tip section, and assure the root separates first - no tip stall. If strip ailerons are drooped the camber along the whole span increases so the wing is as likely to tip stall as without drooped ailerons.