In Triangle by David von Drehle, why was Charley Rose hired to beat up Clara Lemlich?

In the book, we are told that Charley Rose was hired to beat up Clara Lemlich because of her activist work: she had been guilty of leading a worker's strike at a blouse-making factory in Manhattan.
Charley Rose was a burglar by trade, but he also worked when there was money to be made. In other words, he was not averse to working as a mercenary-for-hire whenever the occasion suited him. Meanwhile, Clara Lemlich was an immigrant employee who worked at the blouse-making and shirtwaist factories of New York City. She often led demonstrations to agitate for better pay and working conditions for garment workers.
With a handful of other young women, Clara joined the International Ladies' Garment Workers' Union in 1906 and subsequently set up Local 25 as a local chapter. Clara's Local 25 was largely ignored by the larger male workers' unions; many of the men viewed the female workers as competition, and they felt that the women were unreliable at best in the fight for workers' rights.
However, Clara was an indomitable young woman, despite standing less than five feet tall. She led demonstrations and was indefatigable in her efforts to agitate for better working conditions for all female garment workers. In the end, her activism made her unpopular among the factory owners. Charley Rose was hired to beat Clara up. He brought along with him William Lustig (an amateur boxer) and other shady characters from the New York underworld.
After the men were finished, Clara was left for dead with bruises and broken ribs. However, she survived and became both a socialist martyr and a catalyst for the growth of the workers' movement in New York City.