'Less' IS more; when it comes to an adult, taking down a six-year-old.
We might imagine; that having a Guard approaching him with a taser might have helped escalate his deperate response as well. Nowhere in this story does it indicate that any other measures were tried; including having a parent show up; or another trusted adult/teacher. . .whomever.
Or just the tried option of having to stay in a room with a Guard and/or principlal, who as adults; have more patience than a child whose emotions are out of control.
A delivery of fifty-thousand volts to a child; is an unacceptable option. IMHO. . .
The article indicates that they had already tried talking him down. His response was to inflict further injury on himself by cutting his leg. See the fifth paragraph, as follows:
The officers talked to the boy without success. When he cut his own leg, one officer shocked him with a Taser, then another grabbed him to prevent him from falling, police said.
The Taser prevented the kid from hurting himself any more than he already had, and from stabbing the officer who grabbed him.