Hmmm, with 78 kg I have a huge overlap between the 3 and 4 m2 so no problem for me.
Can almost choose which one I want to ride, the 3 or the 4, in a given wind strength.
The 5 and 6 are very close though, even closer than the percentual difference - because the 5 is faster than the 6, the power is closer.
Same with the 3 and 4 m2, close in low end.
Using them on 21 m lines, std bar.
If you use shorter lines, the gap will probably be smaller is my guess.
Because the 3 and 4 are so close in low end, I have now rigged the 3 m2 on shorter lines, just to see if it works, so the gap is a bit bigger.
My guess is, that they want to have a smaller kite, as the 3 will get too big quite fast.
And keeping the 3 means they have to go down to 2 m2, which might be a size very few will get, OR have the dilemma, should you jump from 4 to 2 m2 which is a huge step, or take the expensive way and get a 4 and 3 and 2?
So maybe a 2½ m2 works okay in a quiver - dont know, we will see
Peter