If the mission is to build a successful small LAR airplane that can operate in and out of a small field the formula is fairly simple.

1. Keep the wing loading as low as possible, and the power loading as high as possible.

2. Choose a planform that provides the greatest wing area for a given span - you would say that would be a square, the caveat is that the leading and trailing edges have to have the shape required to form and maintain a stable vortex at high angles of attack ie. circular, semi-circular, elliptical etc. This is required for low speed stability, to make the machine stall and spin resistant. It is possible that the shape can be deltoid, but a simple delta won’t provide a progressive vortex formation and a double delta (SAAB Draken) can do the opposite and can promote deep stall.

3. An undercarriage that allows 15+ deg. rotation.

The above restrictions are why you don’t see a large number of LAR airplanes, the formula only works for simple single seat aircraft where the payload is small, to get the required wing area to carry a greater payload increases the surface area and therefore the parasite drag and becomes inefficient.