The smaller area of the J-10A wing is also the reason why its winds are not clipped at both ends (making the area even smaller), like the rest of the above examples, which would then otherwise make possible a wind tip rail to be installed.
But then, this really depends on the design requirement. A larger wind area would give more lifts but at the same time that would result in an increase in drag especially at the higher speed regime. So in the end a compromise has to be made according to the different performance requirements expected of the different aircraft.
Another thing I forgot to add is that, generally, the closer the canards are coupled to the winds, the larger is the wind area, so as to increase the effectiveness of the elevons. Example being the Rafale fighter.
