I recently watched a particularly awful cartoon about Superman and Shazaam, and was struck by the nonsensical fighting in mid-air. Martial arts greatly depends on leverage. Punches, kicks, dodges and throws generally involve at least one foot on the ground or forward motion. RPG rules should include at least a nod to Newton's laws of motion. A flier striking someone hard enough to send him soaring away would move backwards (or spin) at great speed also, unless the strike involved an instant whole-body acceleration in the same direction as the strike. If the flier is capable of such sudden, massive acceleration, then the flier would be able to evade or roll with strikes, and may also be immune to injury from strikes by virtue of the inherent resistance to huge forces necessary to survive his own ability to accelerate.
Strength is nearly meaningless in flight. A person's strength is based on his ability to use leverage of joints and of the body against a stable surface. If the Hulk was able to very slowly levitate himself into the air, he would not be able to do so while holding a car. If Banner is able to accelerate very rapidly to great speeds, he would be able to slowly lift a car into the air, perhaps only by pressing his entire body flat underneath it. The point is that both lifting and flying are applications of force, and are not independent of each other in the air.
What systems take any of this into consideration? Aberrant does not, but does include mechanics for additional effectiveness of certain aerial and high-speed maneuvers. There is no prohibition of fliers using their full strength or martial arts ability and damage in the air.
I don't think that it is practical to have an RPG require all the math to precisely simulate fighting and lifting in flight, but I would like to at least see some general penalties or restrictions.