Shahnavaz Azad, 27, and Mohammed Azad, 21, both of Nicholas Close, Watford appeared at St Albans crown courts on a video link from Pentonville jail.
Last week Aamir Mustafa, aged 22, of St George’s Road, Watford, and Mohammed Hamza Shah, 19, of Hagden Lane, Watford were also remanded in custody.
Mr O’Connell, 27, was stabbed during a fight which followed a three-car crash in Watford just before 3am on Saturday August 31st. He was taken to hospital where he was pronounced dead.
Judge Michael Kay QC remanded both men in custody for a plea hearing on 3rd December.
A trial date, expected to last six weeks, has now been set for March 2.