first conference

At the first conference you will have to decide who is who: who in the group will be each of the four roles.  The decision is best reached after an open discussion. 

editor in chief

If you do not have four members but only three - it is the editor in chief who disappears.  Decisions will have to be made at conferences instead.

overlap

At this first conference you should also lay down guidelines beforehand on how autonomous each of these functions is.  Who, for example, has the final word on layout if the layout editor cannot agree with the others?