How many number two or three assistants (or key leaders) does al Qaeda employ?

I obviously disagree with the aims and methods of al Qaeda. However, there is one western custom they seem to have adopted. I'm of course referring to developing burdensome bureaucracy. It seems at least once a week there is a story like this one saying

Multi-national security forces have captured a key associate of Iraq's most wanted terrorist, Abu Musab al-Zarqawi