According to group riding gurus, the lead rider should be on the left (inside) lane in a staggered formation. He has to be able to see when it's clear to pass or change lanes (4-lane).
Hopefully, the guys behind the leader would have the benefit of the entire group being much easer to see. The worst problem I've encountered is when the some of the group let too much space get in formation and cagers try to "shoot the gaps".
