That followed a July 12 incident at the building site at 12th and Wood streets, where developers Michael and Matthew Pestronk were converting a 10-story loft into 163 apartments.
Efforts to reach the men's attorney, Joel Trigiani, who also represents the Laborers District Council of Philadelphia and Laborers Local 332, were unsuccessful.
The Pestronk brothers attempted to employ a mix of union and nonunion workers, the first time in decades that anyone tried to build a major project here without an all-union workforce.
Michael Pestronk on Wednesday called the men's admittance to the diversionary program "grossly unfair."
"These men are violent criminals and they deserved jail time," he said.
A siege developed at the site, with workers beaten, car tires slashed, and delivery trucks blocked for hours. In September, U.S. Rep. Bob Brady (D., Phila.) brokered a deal that ended union picketing of the $38 million project.
Pestronk said picketing had resumed recently, and that he gave police video evidence of a violent incident that occurred Dec. 3.
Court records show that Municipal Court Judge Thomas Gehret granted a motion on Tuesday to allow both defendants to enter into the Accelerated Misdemeanor Program rather than contesting the charges at trial.
The program, established to handle less-serious misdemeanor cases that can clog the Philadelphia court system, can accept defendants charged with such offenses as drug possession, retail theft and prostitution.
Tasha Jamerson, spokesperson for the District Attorney's Office, said the men were eligible for the program because a charge of simple assault is a misdemeanor.
Defendants who agree to community service and a fine do not go to trial and may have their record expunged.
Contact staff writer Jeff Gammage at 215-854-2415, jgammage@phillynews.com, or on Twitter @JeffGammage.