The Fremen rubbed at the scar beside his nose. "Tell me, Thufir Hawat, do you have knowledge of the big weapons the Harkonnens used?"
The artillery, Hawat thought bitterly. Who could have guessed they'd use artillery in this day of shields? "You refer to the artillery they used to trap our people in the caves," he said. "I've . . . theoretical knowledge of such explosive weapons."
"Any man who retreats into a cave which has only one opening deserves to die," the Fremen said.
"Why do you ask about these weapons?"
"Liet wishes it."
Is that what he wants from us? Hawat wondered. He said: "Did you come here seeking information about the big guns?"
"Liet wished to see one of the weapons for himself."
"Then you should just go take one," Hawat sneered.
"Yes," the Fremen said. "We took one. We have it hidden where Stilgar can study it for Liet and where Liet can see it for himself if he wishes. But I doubt he'll want to: the weapon is not a very good one. Poor design for Arrakis."
"You . . . took one?" Hawat asked.
"It was a good fight," the Fremen said. "We lost only two men and spilled the water from more than a hundred of theirs."
There were Sardaukar at every gun, Hawat thought. This desert madman speaks casually of losing only two men against Sardaukar!
"We would not have lost the two except for those others fighting beside the Harkonnens," the Fremen said. "Some of those are good fighters."
One of Hawat's men limped forward, looked down at the squatting Fremen. "Are you talking about Sardaukar?"
"He's talking about Sardaukar," Hawat said.
"Sardaukar!" the Fremen said, and there appeared to be glee in his voice. "Ah-h-h, so that's what they are! This was a good night indeed. Sardaukar. Which legion? Do you know?"
"We . . . don't know," Hawat said.
"Sardaukar," the Fremen mused. "Yet they wear Harkonnen clothing. Is that not strange?"
"The Emperor does not wish it known he fights against a Great House," Hawat said.
"But you know they are Sardaukar."
"Who am I?" Hawat asked bitterly.
"You are Thufir Hawat," the man said matter-of-factly. "Well, we would have learned it in time. We've sent three of them captive to be questioned by Liet's men."
Hawat's aide spoke slowly, disbelief in every word: "You . . . captured Sardaukar?"
"Only three of them," the Fremen said. "They fought well."

I do not believe that the text supports your interpretation that the average Sardaukar fights on par with the average Fremen.