"The CNT-FAI was heavily repressed by the Soviets. Source: CNT". Well, that's not too convincing, I expected some historical research providing numerical data, not the opinions of a CNT member.

Modern estimates of NKVD murders of whom they considered counter-revolutionaries in Republican Spain during the Civil War show 20 proven murders by a total of 10 agents. The book you quoted has no sourcing, it's just the ramblings of a CNT member that we're supposed to take for true. It propagates made-up speculations such as the supposed torture of Andreu Nin at the hands of the Soviets (zero evidence), and makes no effort whatsoever to bring any number to the total of anarchists repressed. It talks of 3500 fascists repressed by the SIM (a Spanish organization, not Soviet), so Anarchists were likely numbered at most in the hundreds, but again, you provide no numerical evidence for your claims.

It's unbearable as a Spaniard hearing these hearsay "if the Soviets hadn't sabotaged the anarchists, they may have won the war", as if the Soviets didn't provide the very weapons the Anarchists were using. No effort in actual data recounting is done, just shameless anti-Soviet propaganda based on literal fabrications like the torturing of Andreu Nin, and the total disregard for the actually logical repression of some anarchists and Trotskyists who, knowingly or not, were collaborating with the Nazis as proven by Harro Shulze-Boysen, a German spy who spied for the soviets and was executed when the Nazis uncovered that he had warned the Soviets about a Nazi plot to have an anarchist revolution in Barcelona to weaken the Republic and make the defeat easier: Link

This was the same insurrection independently reported to the Centre by the Soviet embassy in Berlin after receiving an anonymous tip-off from their agent Harro Schulze- Boysen. From contacts on the Luftwaffe General Staff he revealed that German agents had also infiltrated Trotskyists circles in Barcelona with the intention of encouraging their putsch

Now, bring some numerical historical evidence supporting your claim of massive repressions against anarchists by the Soviets which led to them losing the war