RE: Aero kombat 117 and fin
On a wave, I don't think the width will "generate more power". The 2006 original 30 cm wave fin also sails small for its stated size (just like the Drake Natural wave fin - similar planform).
In a straight line I don't think the width influences this so much either except that if it is choppy, a wider board will adapt to the chopp less good and hence the fin will see more air. This will make a slightly longer fin more forgiving.