Of course leadership is an important factor in any teamwork success, leader guide people to the right way (achieve goals), motivate team members and finally monitor and measure the work progress
absence of leadership means non of the above will be done :(
in other hand if team has more than leader unfortunately also non of the above will be done :O
how come ?!!! a team leader can do that all, so if we have two team leaders they should perform better !!
unfortunately that is not 100% right, two leaders inside single team can lead team to nothing, because most probably if they are lazy they will depend on each other and if they are active they will give contradictory decisions that make confusion for team members
decision making process should be centralized as much as possible, no problem to let members share in some decision as team may include talented personalities but always final decision should be approved by team leader;
Finally there is an old Egyptian quote says,
“ship with two sailors must be sink” :)
