Don't take me wrong, I like Jack, I'm following BC after all, but it's a mismatch.
The slash was cool because of the scale and range.
But taking into account how his slicing magic takes time to adapt to his opponent's magics... and this attack was, by his own admission, a "one in a lifetime super final slash"... Kenpachi did a similar slash casually by swinging his sword with two hands for the first time. Gotei captains are built much different than Clover captains stat-wise.