It's a social problem more than a game mechanic problem. In NA when someone tries to get the team together to do something, it'll work like 1/3 of the time. The other 2/3, what I call "you can't tell me what to do!" syndrome kicks in and 10 players on the team given a 30v30 will do the exact opposite of what you asked. Doesn't matter if you're abrasive, calm, encouraging, or anything. For some reason people will attempt to spite anyone trying to make order, and a greater multiplier for his/her team. Maybe it's just an NA problem, I don't know. When I have played on EU it seemed little different, but there wasn't as much of an exchange like this:
"Hey guys, please stay near this big ole' flag i'm putting on myself, let's stay together here"
"lol no"
"ur not my real dad xDD"
"hay guys lets just run around :DDDD"
"everyone run from the flag LOL"