Good of Kumamae is making spike through between the hands of blocking as she can stay up longer in the air. It's important skill since they have disadvantage of height. S peaking of skill, it would be Ikumi Ogake in Japan team. Only 173cm attacker couldn't be the ace of national team without having that skill, or unless she had amazing jumping like Mireya Luis. Ogake knows well enough how to spike against high wall as getting off the block for instance.
Point is point no matter how.
Since Japan can't have high powerful spiker, they are necessarily required brushing up this kind of trick. M ost impressive play of Japan was blocking by Naomi Eto and Junko Moriyama. They succeeded at block continuously in some points. Also using one leg spike of Moriyama was really efficient. Japan team at least has shaped their own volleyball style, comparing to in 1997 when new Japan team was born under head coach Kuzuwa.