Why are you assuming that the people stabbed were the fascists TWP members?

You left out the quote from two paragraphs later:

Matthew Heimbach, leader of the Traditionalist Worker Party, was not at the rally but told CNN that TWP members armed themselves with knives, with blades within the California legal limit. He said they'd been threatened on social media forums. An affiliate group, the Golden State Skinheads, joined them for the rally, he said.

The TWP was charged by a group that describes itself as anti-fascist, he said.
"The anti-fascists used knives, bottles, bricks, and chunks of concrete they broke off a construction site. When they attacked, our men defended themselves to be able to drive the attackers off," he said.

Heimbach said two "comrades" were hurt -- one stabbed and the other hit in the face with a bottle.

That corroborates a quote in a Guardian article, in which Heimbach made his intention to commit violence crystal clear:

In a post to the organization’s website, Heimbach wrote that he was aware of plans to counter-protest but said: “After carefully weighing the pros and cons, we have decided that this would be our Thermopylae, no matter what it costs.
“We will defend ourselves by any means necessary, and if the police in Sacramento do not protect our right to speak, we will do it ourselves.”

(emphasis mine)

I read another quote this morning, but can't find it now, in which one of the fascists boasted something to the effect of "they got one of ours, but we got six of theirs!". An AP report states that one TWP and six counter-protesters were hospitalized with stab wounds.

Rob, the violence you deplore was planned and instigated by the fascists you defend. And they came out the winners, at least in body count.

It sounds like a setup, an ambush in which the neo-nazis lured in counter-protesters armed with signs and rocks, and attacked them with knives.

They're the ones who brought knives to what should have been a word-fight.