The two men referred to their drug ring as the "Main Line Takeover Project" in texts they sent to each other, prosecutors claim.
Scott, 25, of Haverford, Pa., and Brooks, 18, of Villanova, Pa., were arrested Monday and charged with possession with intent to deliver, conspiracy and other drug-related charges. Their preliminary hearing is May 6.
Nine other high school and college students – so-called "sub-dealers" who worked at each school – were charged with dealing marijuana, hash oil, cocaine and Ecstasy.
"This was not a game. These people were in business," Montgomery County District Attorney Risa Ferman told reporters Monday.
Authorities recovered $11,000 in cash, along with marijuana, cocaine and guns – including an AR-15 assault rifle – in Scott's apartment.
"They were in business to make money," Ferman said, "and they were going to do whatever they needed to do to make sure that no one threatened their business."
Scott is being held on $1 million bail. Brooks was released after posting 10 percent of his $250,000 bail.
Remorse and RegretGreg Pagano, Brooks's attorney, tells PEOPLE his client is "remorseful and truly regrets" his involvement.
"He suffered an injury as an athlete at his first year of college in the fall of 2013 requiring him to return home for surgery and to recuperate," Pagano said via e-mail.
"He became depressed and was not well physically or mentally," Pagano added. "It was during this time period that he became acquainted with the wrong people and began selling marijuana."
Brooks did this for less than three months and possessed no weapons, Pagano claims.
Scott's attorney, Tom Egan, could not be reached for comment.
On Monday at the Haverford School, just west of Philadelphia, from which Brooks and Scott graduated, lacrosse coach John Nostrant was visibly upset after hearing about the arrests of two of his former players.
"It's crushing to me," he told the Philadelphia Daily News as he struggled to hold back tears. "I feel bad for their families. It's a sad day."
Nostrant said that Brooks, who graduated in 2013, was a "very good midfielder," and Scott, who graduated in 2007, was a "solid goalie."