Your approach indeed will work for low cruising speed, providing more efficient lift with multiple higher aspect wings. This is exactly what soaring eagles, condors, and vultures have on their wing tips. These work great for slow circling flight while hunting an area.

However, these wings are speed limited, rapidly producing too much drag at higher speeds.

The albatross uses more speed and lower drag to generate adequate lift and migrate 1000s of miles. Notice the difference in their wings. The entire wing is longer and thinner, without multiple "winglets".

Study of these birds parallels evolution in aircraft design. Engine efficiency improvements and higher speeds at higher altitudes (also an advantage) has lead to the lowest drag mono-wing designs being most common.

But for walking speed free flight models, built light but strong, a thin undercambered very high aspect biplane is a delight to fly. They just have problems making any forward progress in a headwind.

Your approach indeed will work for very low cruising speed, providing more efficient lift with multiple higher aspect wings. This is exactly what soaring eagles, condors, and vultures have on their wing tips. These work great for slow circling flight while hunting an area.

However, these wings are speed limited, rapidly producing too much drag at higher speeds.

The albatross uses more speed and lower drag to generate adequate lift and migrate 1000s of miles. Notice the difference in their wings. The entire wing is longer and thinner, without multiple "winglets".

Study of these birds parallels evolution in aircraft design. Engine efficiency improvements and higher speeds at higher altitudes (also an advantage) has lead to the lowest drag mono-wing designs being most common.

But for walking speed free flight models, built light but strong, a thin undercambered very high aspect biplane is a delight to fly. They just have problems making any forward progress in a headwind.