All of the attorneys said their clients had not been allowed to wear the clothing of their choice to the arraignment.
"These kinds of things inflame the situation," Nevin said.
Attorney James Connell, who represents Abd al-Aziz Ali, described the arraignment as "only the beginning of a trial that will take years to complete, followed by years of appellate review."
"I can't imagine any scenario where this thing gets wrapped up in six months," Connell told reporters at Guantanamo Bay.
The cases are moving forward after the guilty plea of a former Baltimore County man in February.
Majid Shoukat Khan, the first of the 14 so-called high-value detainees at Guantanamo Bay to be convicted, could testify in the trial of his alleged former colleagues.
Khan, a native of Pakistan who landed in Catonsville in 1996 and graduated from Owings Mills High School three years later, pleaded guilty in February to conspiring with Mohammed and al-Qaida leader Osama bin Laden in plots in Indonesia, Pakistan and the United States.
Under his plea agreement, he will serve no more than 19 years for his role in a 2003 suicide car bombing at the J.W. Marriott Hotel in Jakarta that killed 11, provided he gives the government his "full and truthful cooperation."
His testimony is expected to help prosecutors work around evidence obtained through torture.
Sun reporter Steve Kilar and the Associated Press contributed to this article.