ps: one small remark; I think you should reverse the flags on the masttops; the wind blows them in a forwards direction, possibly slightly sidewards...
For the brig, the best wind to sail by came from lateral winds, and the sails should be adjusted at a 45 degree angle to the wind. So the flags should blow somewhere between straight ahead (12 oclock) if the wind is coming behind them, and 9 or 3 o'clock. If the brig was tacking against the wind it could theoretically blow around 8 o clock or 4 o'clock. so it could, theoretically, still blow "backwards" (aft), but at an angle.
the sloops can tack closer to the wind, so the flag might even blow aft even more at 7 or 5 oclock (they'd probably have to furl the square sail and use only the jibbs and the spanker)
