This second set of Red Fox War Planes II also likely originates from China. Its distinction from 'set 1' suggests a variation; it may be a different version, a revision, or an update of the game which may include tweaks in gameplay mechanics, level designs, or even graphical elements.  More information would be needed to provide a precise comparison between the two sets.

Red Fox War Planes II (China, set 2)

Red Earth / War-Zard (Euro 961023)