It's funny, playing arena in World of Warcraft has made me realize how rare it is that people are able to be good leaders. On my warlock's team, I'm the leader, so we have a reasonably good leader. Consequently that team has been fairly successful consistently.
On my priest's team, we continually have problems with coordination because I cannot lead the offense as a priest whose main job is kiting and defensive type stuff. Our main warrior is an awesome guy, but he's of the simple "tell me what to kill and I'll kill it" mindset. Our warlock is trying to step up into a leadership type role, but he honestly lacks the tactical knowledge to make the right calls and quickly. One of our two mages is also very quiet and not confident enough to call plays. Our other mage would be fairly capable to calling plays, but he's not always in the game and he is not the sort who volunteers to do it. When he does it, though, he does a fairly good job. We really need someone on the team to assume the role of leader of the offense.
Being a good leader is not easy. You need to have the confidence and knowledge to quickly call plays that will determine your team's fate. It's not easy to accept the responsibility that a lot of times when you lose, it's your fault for calling the wrong play. You have to have the patience to teach your team what you want them to do better when things go wrong. You have to also have the desire to win so you can inspire your team to keep pushing just a little farther than they thought they were capable of. You have to be able to adapt on the fly as situations arise but you have to still never lose sight of the overall strategy. You need to have the patience to manage the team members and the organization to track people's schedules.
Honestly, when we started my warlock's team, I didn't think we'd be capable of getting much more than an 1850 rating by the end of the season. However, we've come quite far since then, even finishing last week as the number 1 team on my server and 80th overall in the battlegroup.